Section III
Original German
446 Dritter Abschnitt.
Übergang von der Metaphysik der Sitten zur Kritik der reinen praktischen Vernunft.
Der Begriff der Freiheit ist der Schlüssel zur Erklärung der Autonomie des Willens.
Der Wille ist eine Art von Causalität lebender Wesen, so fern sie vernünftig sind, und Freiheit würde diejenige Eigenschaft dieser Causalität sein, da sie unabhängig von fremden sie bestimmenden Ursachen wirkend sein kann: so wie Naturnothwendigkeit die Eigenschaft der Causalität aller vernunftlosen Wesen, durch den Einfluß fremder Ursachen zur Thätigkeit bestimmt zu werden.
Die angeführte Erklärung der Freiheit ist negativ und daher, um ihr Wesen einzusehen, unfruchtbar; allein es fließt aus ihr ein positiver Begriff derselben, der desto reichhaltiger und fruchtbarer ist. Da der Begriff einer Causalität den von Gesetzen bei sich führt, nach welchen durch etwas, was wir Ursache nennen, etwas anderes, nämlich die Folge, gesetzt werden muß: so ist die Freiheit, ob sie zwar nicht eine Eigenschaft des Willens nach Naturgesetzen ist, darum doch nicht gar gesetzlos, sondern muß vielmehr eine Causalität nach unwandelbaren Gesetzen, aber von besonderer Art sein; denn sonst wäre ein freier Wille ein Unding. Die Naturnothwendigkeit war eine Heteronomie der wirkenden Ursachen; denn jede Wirkung war nur nach dem Gesetze möglich, daß etwas anderes die wirkende Ursache zur Causalität bestimmte; was kann denn wohl die Freiheit
447 des Willens sonst sein als Autonomie, d. i. die Eigenschaft des Willens, sich selbst ein Gesetz zu sein? Der Satz aber: der Wille ist in allen Handlungen sich selbst ein Gesetz, bezeichnet nur das Princip, nach keiner anderen Maxime zu handeln, als die sich selbst auch als ein allgemeines Gesetz zum Gegenstande haben kann. Dies ist aber gerade die Formel des kategorischen Imperativs und das Princip der Sittlichkeit: also ist ein freier Wille und ein Wille unter sittlichen Gesetzen einerlei.
Wenn also Freiheit des Willens vorausgesetzt wird, so folgt die Sittlichkeit sammt ihrem Princip daraus durch bloße Zergliederung ihres Begriffs. Indessen ist das letztere doch immer ein synthetischer Satz: ein schlechterdings guter Wille ist derjenige, dessen Maxime jederzeit sich selbst, als allgemeines Gesetz betrachtet, in sich enthalten kann, denn durch Zergliederung des Begriffs von einem schlechthin guten Willen kann jene Eigenschaft der Maxime nicht gefunden werden. Solche synthetische Sätze sind aber nur dadurch möglich, daß beide Erkenntnisse durch die Verknüpfung mit einem dritten, darin sie beiderseits anzutreffen sind, unter einander verbunden werden. Der positive Begriff der Freiheit schafft dieses dritte, welches nicht wie bei den physischen Ursachen die Natur der Sinnenwelt sein kann (in deren Begriff die Begriffe von etwas als Ursache in Verhältniß auf etwas anderes als Wirkung zusammenkommen). Was dieses dritte sei, worauf uns die Freiheit weiset, und von dem wir a priori eine Idee haben, läßt sich hier sofort noch nicht anzeigen und die Deduction des Begriffs der Freiheit aus der reinen praktischen Vernunft, mit ihr auch die Möglichkeit eines kategorischen Imperativs begreiflich machen, sondern bedarf noch einiger Vorbereitung.
Freiheit muß als Eigenschaft des Willens aller vernünftigen Wesen vorausgesetzt werden.
Es ist nicht genug, daß wir unserem Willen, es sei aus welchem Grunde, Freiheit zuschreiben, wenn wir nicht ebendieselbe auch allen vernünftigen Wesen beizulegen hinreichenden Grund haben. Denn da Sittlichkeit für uns bloß als für vernünftige Wesen zum Gesetze dient, so muß sie auch für alle vernünftige Wesen gelten, und da sie lediglich aus der Eigenschaft der Freiheit abgeleitet werden muß, so muß auch Freiheit als Eigenschaft des Willens aller vernünftigen Wesen bewiesen werden, und es ist nicht genug, sie aus gewissen vermeintlichen Erfahrungen
448 von der menschlichen Natur darzuthun (wiewohl dieses auch schlechterdings unmöglich ist und lediglich a priori dargethan werden kann), sondern man muß sie als zur Thätigkeit vernünftiger und mit einem Willen begabter Wesen überhaupt gehörig beweisen. Ich sage nun: Ein jedes Wesen, das nicht anders als unter der Idee der Freiheit handeln kann, ist eben darum in praktischer Rücksicht wirklich frei, d. i. es gelten für dasselbe alle Gesetze, die mit der Freiheit unzertrennlich verbunden sind, eben so als ob sein Wille auch an sich selbst und in der theoretischen Philosophie gültig für frei erklärt würde*). Nun behaupte ich: daß wir jedem vernünftigen Wesen, das einen Willen hat, nothwendig auch die Idee der Freiheit leihen müssen, unter der es allein handle. Denn in einem solchen Wesen denken wir uns eine Vernunft, die praktisch ist, d. i. Causalität in Ansehung ihrer Objecte hat. Nun kann man sich unmöglich eine Vernunft denken, die mit ihrem eigenen Bewußtsein in Ansehung ihrer Urtheile anderwärts her eine Lenkung empfinge, denn alsdann würde das Subject nicht seiner Vernunft, sondern einem Antriebe die Bestimmung der Urtheilskraft zuschreiben. Sie muß sich selbst als Urheberin ihrer Principien ansehen unabhängig von fremden Einflüssen, folglich muß sie als praktische Vernunft, oder als Wille eines vernünftigen Wesens von ihr selbst als frei angesehen werden; d. i. der Wille desselben kann nur unter der Idee der Freiheit ein eigener Wille sein und muß also in praktischer Absicht allen vernünftigen Wesen beigelegt werden.
Von dem Interesse, welches den Ideen der Sittlichkeit anhängt.
Wir haben den bestimmten Begriff der Sittlichkeit auf die Idee der Freiheit zuletzt zurückgeführt; diese aber konnten wir als etwas Wirkliches nicht einmal in uns selbst und in der menschlichen Natur beweisen; wir
*) Diesen Weg, die Freiheit nur als von vernünftigen Wesen bei ihren Handlungen bloß in der Idee zum Grunde gelegt zu unserer Absicht hinreichend anzunehmen, schlage ich deswegen ein, damit ich mich nicht verbindlich machen dürfte, die Freiheit auch in ihrer theoretischen Absicht zu beweisen. Denn wenn dieses letztere auch unausgemacht gelassen wird, so gelten doch dieselben Gesetze für ein Wesen, das nicht anders als unter der Idee seiner eigenen Freiheit handeln kann, die ein Wesen, das wirklich frei wäre, verbinden würden. Wir können uns hier also von der Last befreien, die die Theorie drückt.
449 sahen nur, daß wir sie voraussetzen müssen, wenn wir uns ein Wesen als vernünftig und mit Bewußtsein seiner Causalität in Ansehung der Handlungen, d. i. mit einem Willen, begabt uns denken wollen, und so finden wir, daß wir aus eben demselben Grunde jedem mit Vernunft und Willen begabten Wesen diese Eigenschaft, sich unter der Idee seiner Freiheit zum Handeln zu bestimmen, beilegen müssen.
Es floß aber aus der Voraussetzung dieser Ideen auch das Bewußtsein eines Gesetzes zu handeln: daß die subjectiven Grundsätze der Handlungen, d. i. Maximen, jederzeit so genommen werden müssen, daß sie auch objectiv, d. i. allgemein als Grundsätze, gelten, mithin zu unserer eigenen allgemeinen Gesetzgebung dienen können. Warum aber soll ich mich denn diesem Princip unterwerfen und zwar als vernünftiges Wesen überhaupt, mithin auch dadurch alle andere mit Vernunft begabte Wesen? Ich will einräumen, daß mich hiezu kein Interesse treibt, denn das würde keinen kategorischen Imperativ geben; aber ich muß doch hieran nothwendig ein Interesse nehmen und einsehen, wie das zugeht; denn dieses Sollen ist eigentlich ein Wollen, das unter der Bedingung für jedes vernünftige Wesen gilt, wenn die Vernunft bei ihm ohne Hindernisse praktisch wäre; für Wesen, die wie wir noch durch Sinnlichkeit als Triebfedern anderer Art afficirt werden, bei denen es nicht immer geschieht, was die Vernunft für sich allein thun würde, heißt jene Nothwendigkeit der Handlung nur ein Sollen, und die subjective Nothwendigkeit wird von der objectiven unterschieden.
Es scheint also, als setzten wir in der Idee der Freiheit eigentlich das moralische Gesetz, nämlich das Princip der Autonomie des Willens selbst, nur voraus und könnten seine Realität und objective Nothwendigkeit nicht für sich beweisen, und da hätten wir zwar noch immer etwas ganz Beträchtliches dadurch gewonnen, daß wir wenigstens das ächte Princip genauer, als wohl sonst geschehen, bestimmt hätten, in Ansehung seiner Gültigkeit aber und der praktischen Nothwendigkeit, sich ihm zu unterwerfen, wären wir um nichts weiter gekommen; denn wir könnten dem, der uns fragte, warum denn die Allgemeingültigkeit unserer Maxime, als eines Gesetzes, die einschränkende Bedingung unserer Handlungen sein müsse, und worauf wir den Werth gründen, den wir dieser Art zu handeln beilegen, der so groß sein soll, daß es überall kein höheres Interesse geben kann, und wie es zugehe, daß der Mensch dadurch allein seinen persönlichen Werth zu
450 fühlen glaubt, gegen den der eines angenehmen oder unangenehmen Zustandes für nichts zu halten sei, keine genugthuende Antwort geben.
Zwar finden wir wohl, daß wir an einer persönlichen Beschaffenheit ein Interesse nehmen können, die gar kein Interesse des Zustandes bei sich führt, wenn jene uns nur fähig macht, des letzteren theilhaftig zu werden, im Falle die Vernunft die Austheilung desselben bewirken sollte, d. i. daß die bloße Würdigkeit, glücklich zu sein, auch ohne den Bewegungsgrund, dieser Glückseligkeit theilhaftig zu werden, für sich interessiren könne: aber dieses Urtheil ist in der That nur die Wirkung von der schon vorausgesetzten Wichtigkeit moralischer Gesetze (wenn wir uns durch die Idee der Freiheit von allem empirischen Interesse trennen); aber daß wir uns von diesem trennen, d. i. uns als frei im Handeln betrachten und so uns dennoch für gewissen Gesetzen unterworfen halten sollen, um einen Werth bloß in unserer Person zu finden, der uns allen Verlust dessen, was unserm Zustande einen Werth verschafft, vergüten könne, und wie dieses möglich sei, mithin woher das moralische Gesetz verbinde, können wir auf solche Art noch nicht einsehen.
Es zeigt sich hier, man muß es frei gestehen, eine Art von Cirkel, aus dem, wie es scheint, nicht heraus zu kommen ist. Wir nehmen uns in der Ordnung der wirkenden Ursachen als frei an, um uns in der Ordnung der Zwecke unter sittlichen Gesetzen zu denken, und wir denken uns nachher als diesen Gesetzen unterworfen, weil wir uns die Freiheit des Willens beigelegt haben; denn Freiheit und eigene Gesetzgebung des Willens sind beides Autonomie, mithin Wechselbegriffe, davon aber einer eben um deswillen nicht dazu gebraucht werden kann, um den anderen zu erklären und von ihm Grund anzugeben, sondern höchstens nur, um in logischer Absicht verschiedene scheinende Vorstellungen von eben demselben Gegenstande auf einen einzigen Begriff (wie verschiedne Brüche gleiches Inhalts auf die kleinsten Ausdrücke) zu bringen.
Eine Auskunft bleibt uns aber noch übrig, nämlich zu suchen: ob wir, wenn wir uns durch Freiheit als a priori wirkende Ursachen denken, nicht einen anderen Standpunkt einnehmen, als wenn wir uns selbst nach unseren Handlungen als Wirkungen, die wir vor unseren Augen sehen, uns vorstellen.
Es ist eine Bemerkung, welche anzustellen eben kein subtiles Nachdenken erfordert wird, sondern von der man annehmen kann, daß sie wohl der gemeinste Verstand, obzwar nach seiner Art durch eine dunkele Unterscheidung
451 der Urtheilskraft, die er Gefühl nennt, machen mag: daß alle Vorstellungen, die uns ohne unsere Willkür kommen (wie die der Sinne), uns die Gegenstände nicht anders zu erkennen geben, als sie uns afficiren, wobei, was sie an sich sein mögen, uns unbekannt bleibt, mithin daß, was diese Art Vorstellungen betrifft, wir dadurch auch bei der angestrengtesten Aufmerksamkeit und Deutlichkeit, die der Verstand nur immer hinzufügen mag, doch bloß zur Erkenntniß der Erscheinungen, niemals der Dinge an sich selbst gelangen können. Sobald dieser Unterschied (allenfalls bloß durch die bemerkte Verschiedenheit zwischen den Vorstellungen, die uns anders woher gegeben werden, und dabei wir leidend sind, von denen, die wir lediglich aus uns selbst hervorbringen, und dabei wir unsere Thätigkeit beweisen) einmal gemacht ist, so folgt von selbst, daß man hinter den Erscheinungen doch noch etwas anderes, was nicht Erscheinung ist, nämlich die Dinge an sich, einräumen und annehmen müsse, ob wir gleich uns von selbst bescheiden, daß, da sie uns niemals bekannt werden können, sondern immer nur, wie sie uns afficiren, wir ihnen nicht näher treten und, was sie an sich sind, niemals wissen können. Dieses muß eine, obzwar rohe, Unterscheidung einer Sinnenwelt von der Verstandeswelt abgeben, davon die erstere nach Verschiedenheit der Sinnlichkeit in mancherlei Weltbeschauern auch sehr verschieden sein kann, indessen die zweite, die ihr zum Grunde liegt, immer dieselbe bleibt. Sogar sich selbst und zwar nach der Kenntniß, die der Mensch durch innere Empfindung von sich hat, darf er sich nicht anmaßen zu erkennen, wie er an sich selbst sei. Denn da er doch sich selbst nicht gleichsam schafft und seinen Begriff nicht a priori, sondern empirisch bekommt, so ist natürlich, daß er auch von sich durch den innern Sinn und folglich nur durch die Erscheinung seiner Natur und die Art, wie sein Bewußtsein afficirt wird, Kundschaft einziehen könne, indessen er doch nothwendiger Weise über diese aus lauter Erscheinungen zusammengesetzte Beschaffenheit seines eigenen Subjects noch etwas anderes zum Grunde Liegendes, nämlich sein Ich, wie es an sich selbst beschaffen sein mag, annehmen und sich also in Absicht auf die bloße Wahrnehmung und Empfänglichkeit der Empfindungen zur Sinnenwelt, in Ansehung dessen aber, was in ihm reine Thätigkeit sein mag, (dessen, was gar nicht durch Afficirung der Sinne, sondern unmittelbar zum Bewußtsein gelangt) sich zur intellectuellen Welt zählen muß, die er doch nicht weiter kennt.
Dergleichen Schluß muß der nachdenkende Mensch von allen Dingen,
452 die ihm vorkommen mögen, fällen; vermuthlich ist er auch im gemeinsten Verstande anzutreffen, der, wie bekannt, sehr geneigt ist, hinter den Gegenständen der Sinne noch immer etwas Unsichtbares, für sich selbst Thätiges zu erwarten, es aber wiederum dadurch verdirbt, daß er dieses Unsichtbare sich bald wiederum versinnlicht, d. i. zum Gegenstande der Anschauung machen will, und dadurch also nicht um einen Grad klüger wird.
Nun findet der Mensch in sich wirklich ein Vermögen, dadurch er sich von allen andern Dingen, ja von sich selbst, so fern er durch Gegenstände afficirt wird, unterscheidet, und das ist die Vernunft. Diese, als reine Selbstthätigkeit, ist sogar darin noch über den Verstand erhoben: daß, obgleich dieser auch Selbstthätigkeit ist und nicht wie der Sinn bloß Vorstellungen enthält, die nur entspringen, wenn man von Dingen afficirt (mithin leidend) ist, er dennoch aus seiner Thätigkeit keine andere Begriffe hervorbringen kann als die, so bloß dazu dienen, um die sinnlichen Vorstellungen unter Regeln zu bringen und sie dadurch in einem Bewußtsein zu vereinigen, ohne welchen Gebrauch der Sinnlichkeit er gar nichts denken würde, da hingegen die Vernunft unter dem Namen der Ideen eine so reine Spontaneität zeigt, daß sie dadurch weit über alles, was ihr Sinnlichkeit nur liefern kann, hinausgeht und ihr vornehmstes Geschäfte darin beweiset, Sinnenwelt und Verstandeswelt von einander zu unterscheiden, dadurch aber dem Verstande selbst seine Schranken vorzuzeichnen.
Um deswillen muß ein vernünftiges Wesen sich selbst als Intelligenz (also nicht von Seiten seiner untern Kräfte), nicht als zur Sinnen-, sondern zur Verstandeswelt gehörig, ansehen; mithin hat es zwei Standpunkte, daraus es sich selbst betrachten und Gesetze des Gebrauchs seiner Kräfte, folglich aller seiner Handlungen erkennen kann, einmal, so fern es zur Sinnenwelt gehört, unter Naturgesetzen (Heteronomie), zweitens, als zur intelligibelen Welt gehörig, unter Gesetzen, die, von der Natur unabhängig, nicht empirisch, sondern bloß in der Vernunft gegründet sind.
Als ein vernünftiges, mithin zur intelligibelen Welt gehöriges Wesen kann der Mensch die Causalität seines eigenen Willens niemals anders als unter der Idee der Freiheit denken; denn Unabhängigkeit von den bestimmenden Ursachen der Sinnenwelt (dergleichen die Vernunft jederzeit sich selbst beilegen muß) ist Freiheit. Mit der Idee der Freiheit ist nun der Begriff der Autonomie unzertrennlich verbunden, mit diesem aber das allgemeine Princip der Sittlichkeit, welches in der Idee allen Handlungen
453 vernünftiger Wesen eben so zum Grunde liegt, als das Naturgesetz allen Erscheinungen.
Nun ist der Verdacht, den wir oben rege machten, gehoben, als wäre ein geheimer Cirkel in unserem Schlusse aus der Freiheit auf die Autonomie und aus dieser aufs sittliche Gesetz enthalten, daß wir nämlich vielleicht die Idee der Freiheit nur um des sittlichen Gesetzes willen zum Grunde legten, um dieses nachher aus der Freiheit wiederum zu schließen, mithin von jenem gar keinen Grund angeben könnten, sondern es nur als Erbittung eines Princips, das uns gutgesinnte Seelen wohl gerne einräumen werden, welches wir aber niemals als einen erweislichen Satz aufstellen könnten. Denn jetzt sehen wir, daß, wenn wir uns als frei denken, so versetzen wir uns als Glieder in die Verstandeswelt und erkennen die Autonomie des Willens sammt ihrer Folge, der Moralität; denken wir uns aber als verpflichtet, so betrachten wir uns als zur Sinnenwelt und doch zugleich zur Verstandeswelt gehörig.
Wie ist ein kategorischer Imperativ möglich?
Das vernünftige Wesen zählt sich als Intelligenz zur Verstandeswelt, und bloß als eine zu dieser gehörige wirkende Ursache nennt es seine Causalität einen Willen. Von der anderen Seite ist es sich seiner doch auch als eines Stücks der Sinnenwelt bewußt, in welcher seine Handlungen als bloße Erscheinungen jener Causalität angetroffen werden, deren Möglichkeit aber aus dieser, die wir nicht kennen, nicht eingesehen werden kann, sondern an deren Statt jene Handlungen als bestimmt durch andere Erscheinungen, nämlich Begierden und Neigungen, als zur Sinnenwelt gehörig eingesehen werden müssen. Als bloßen Gliedes der Verstandeswelt würden also alle meine Handlungen dem Princip der Autonomie des reinen Willens vollkommen gemäß sein; als bloßen Stücks der Sinnenwelt würden sie gänzlich dem Naturgesetz der Begierden und Neigungen, mithin der Heteronomie der Natur gemäß genommen werden müssen. (Die ersteren würden auf dem obersten Princip der Sittlichkeit, die zweiten der Glückseligkeit beruhen.) Weil aber die Verstandeswelt den Grund der Sinnenwelt, mithin auch der Gesetze derselben enthält, also in Ansehung meines Willens (der ganz zur Verstandeswelt gehört) unmittelbar gesetzgebend ist und also auch als solche gedacht werden muß, so werde ich mich als Intelligenz, obgleich andererseits wie ein zur
454 Sinnenwelt gehöriges Wesen, dennoch dem Gesetze der ersteren, d. i. der Vernunft, die in der Idee der Freiheit das Gesetz derselben enthält, und also der Autonomie des Willens unterworfen erkennen, folglich die Gesetze der Verstandeswelt für mich als Imperativen und die diesem Princip gemäße Handlungen als Pflichten ansehen müssen.
Und so sind kategorische Imperativen möglich, dadurch daß die Idee der Freiheit mich zu einem Gliede einer intelligibelen Welt macht, wodurch, wenn ich solches allein wäre, alle meine Handlungen der Autonomie des Willens jederzeit gemäß sein würden, da ich mich aber zugleich als Glied der Sinnenwelt anschaue, gemäß sein sollen, welches kategorische Sollen einen synthetischen Satz a priori vorstellt, dadurch daß über meinen durch sinnliche Begierden afficirten Willen noch die Idee ebendesselben, aber zur Verstandeswelt gehörigen reinen, für sich selbst praktischen Willens hinzukommt, welcher die oberste Bedingung des ersteren nach der Vernunft enthält; ungefähr so, wie zu den Anschauungen der Sinnenwelt Begriffe des Verstandes, die für sich selbst nichts als gesetzliche Form überhaupt bedeuten, hinzu kommen und dadurch synthetische Sätze a priori, auf welchen alle Erkenntniß einer Natur beruht, möglich machen.
Der praktische Gebrauch der gemeinen Menschenvernunft bestätigt die Richtigkeit dieser Deduction. Es ist niemand, selbst der ärgste Bösewicht, wenn er nur sonst Vernunft zu brauchen gewohnt ist, der nicht, wenn man ihm Beispiele der Redlichkeit in Absichten, der Standhaftigkeit in Befolgung guter Maximen, der Theilnehmung und des allgemeinen Wohlwollens (und noch dazu mit großen Aufopferungen von Vortheilen und Gemächlichkeit verbunden) vorlegt, nicht wünsche, daß er auch so gesinnt sein möchte. Er kann es aber nur wegen seiner Neigungen und Antriebe nicht wohl in sich zu Stande bringen, wobei er dennoch zugleich wünscht, von solchen ihm selbst lästigen Neigungen frei zu sein. Er beweiset hiedurch also, daß er mit einem Willen, der von Antrieben der Sinnlichkeit frei ist, sich in Gedanken in eine ganz andere Ordnung der Dinge versetze, als die seiner Begierden im Felde der Sinnlichkeit, weil er von jenem Wunsche keine Vergnügung der Begierden, mithin keinen für irgend eine seiner wirklichen oder sonst erdenklichen Neigungen befriedigenden Zustand (denn dadurch würde selbst die Idee, welche ihm den Wunsch ablockt, ihre Vorzüglichkeit einbüßen), sondern nur einen größeren inneren Werth seiner Person erwarten kann. Diese bessere Person
455 glaubt er aber zu sein, wenn er sich in den Standpunkt eines Gliedes der Verstandeswelt versetzt, dazu die Idee der Freiheit, d. i. Unabhängigkeit von bestimmenden Ursachen der Sinnenwelt, ihn unwillkürlich nöthigt, und in welchem er sich eines guten Willens bewußt ist, der für seinen bösen Willen als Gliedes der Sinnenwelt nach seinem eigenen Geständnisse das Gesetz ausmacht, dessen Ansehen er kennt, indem er es übertritt. Das moralische Sollen ist also eigenes nothwendiges Wollen als Gliedes einer intelligibelen Welt und wird nur so fern von ihm als Sollen gedacht, als er sich zugleich wie ein Glied der Sinnenwelt betrachtet.
Von der äußersten Grenze aller praktischen Philosophie.
Alle Menschen denken sich dem Willen nach als frei. Daher kommen alle Urtheile über Handlungen als solche, die hätten geschehen sollen, ob sie gleich nicht geschehen sind. Gleichwohl ist diese Freiheit kein Erfahrungsbegriff und kann es auch nicht sein, weil er immer bleibt, obgleich die Erfahrung das Gegentheil von denjenigen Forderungen zeigt, die unter Voraussetzung derselben als nothwendig vorgestellt werden. Auf der anderen Seite ist es eben so nothwendig, daß alles, was geschieht, nach Naturgesetzen unausbleiblich bestimmt sei, und diese Naturnothwendigkeit ist auch kein Erfahrungsbegriff, eben darum weil er den Begriff der Nothwendigkeit, mithin einer Erkenntniß a priori bei sich führt. Aber dieser Begriff von einer Natur wird durch Erfahrung bestätigt und muß selbst unvermeidlich vorausgesetzt werden, wenn Erfahrung, d. i. nach allgemeinen Gesetzen zusammenhängende Erkenntniß der Gegenstände der Sinne, möglich sein soll. Daher ist Freiheit nur eine Idee der Vernunft, deren objective Realität an sich zweifelhaft ist, Natur aber ein Verstandesbegriff, der seine Realität an Beispielen der Erfahrung beweiset und nothwendig beweisen muß.
Ob nun gleich hieraus eine Dialektik der Vernunft entspringt, da in Ansehung des Willens die ihm beigelegte Freiheit mit der Naturnothwendigkeit im Widerspruch zu stehen scheint, und bei dieser Wegescheidung die Vernunft in speculativer Absicht den Weg der Naturnothwendigkeit viel gebähnter und brauchbarer findet, als den der Freiheit: so ist doch in praktischer Absicht der Fußsteig der Freiheit der einzige, auf welchem es möglich ist, von seiner Vernunft bei unserem Thun und Lassen
456 Gebrauch zu machen; daher wird es der subtilsten Philosophie eben so unmöglich, wie der gemeinsten Menschenvernunft, die Freiheit wegzuvernünfteln. Diese muß also wohl voraussetzen: daß kein wahrer Widerspruch zwischen Freiheit und Naturnothwendigkeit ebenderselben menschlichen Handlungen angetroffen werde, denn sie kann eben so wenig den Begriff der Natur, als den der Freiheit aufgeben.
Indessen muß dieser Scheinwiderspruch wenigstens auf überzeugende Art vertilgt werden, wenn man gleich, wie Freiheit möglich sei, niemals begreifen könnte. Denn wenn sogar der Gedanke von der Freiheit sich selbst, oder der Natur, die eben so nothwendig ist, widerspricht, so müßte sie gegen die Naturnothwendigkeit durchaus aufgegeben werden.
Es ist aber unmöglich, diesem Widerspruch zu entgehen, wenn das Subject, was sich frei dünkt, sich selbst in demselben Sinne, oder in eben demselben Verhältnisse dächte, wenn es sich frei nennt, als wenn es sich in Absicht auf die nämliche Handlung dem Naturgesetze unterworfen annimmt. Daher ist es eine unnachlaßliche Aufgabe der speculativen Philosophie: wenigstens zu zeigen, daß ihre Täuschung wegen des Widerspruchs darin beruhe, daß wir den Menschen in einem anderen Sinne und Verhältnisse denken, wenn wir ihn frei nennen, als wenn wir ihn als Stück der Natur dieser ihren Gesetzen für unterworfen halten, und daß beide nicht allein gar wohl beisammen stehen können, sondern auch als nothwendig vereinigt in demselben Subject gedacht werden müssen, weil sonst nicht Grund angegeben werden könnte, warum wir die Vernunft mit einer Idee belästigen sollten, die, ob sie sich gleich ohne Widerspruch mit einer anderen, genugsam bewährten vereinigen läßt, dennoch uns in ein Geschäfte verwickelt, wodurch die Vernunft in ihrem theoretischen Gebrauche sehr in die Enge gebracht wird. Diese Pflicht liegt aber bloß der speculativen Philosophie ob, damit sie der praktischen freie Bahn schaffe. Also ist es nicht in das Belieben des Philosophen gesetzt, ob er den scheinbaren Widerstreit heben, oder ihn unangerührt lassen will; denn im letzteren Falle ist die Theorie hierüber bonum vacans, in dessen Besitz sich der Fatalist mit Grunde setzen und alle Moral aus ihrem ohne Titel besessenen vermeinten Eigenthum verjagen kann.
Doch kann man hier noch nicht sagen, daß die Grenze der praktischen Philosophie anfange. Denn jene Beilegung der Streitigkeit gehört gar nicht ihr zu, sondern sie fordert nur von der speculativen Vernunft, daß diese die Uneinigkeit, darin sie sich in theoretischen Fragen selbst verwickelt,
457 zu Ende bringe, damit praktische Vernunft Ruhe und Sicherheit für äußere Angriffe habe, die ihr den Boden, worauf sie sich anbauen will, streitig machen könnten.
Der Rechtsanspruch aber selbst der gemeinen Menschenvernunft auf Freiheit des Willens gründet sich auf das Bewußtsein und die zugestandene Voraussetzung der Unabhängigkeit der Vernunft von bloß subjectiv-bestimmenden Ursachen, die insgesammt das ausmachen, was bloß zur Empfindung, mithin unter die allgemeine Benennung der Sinnlichkeit gehört. Der Mensch, der sich auf solche Weise als Intelligenz betrachtet, setzt sich dadurch in eine andere Ordnung der Dinge und in ein Verhältniß zu bestimmenden Gründen von ganz anderer Art, wenn er sich als Intelligenz mit einem Willen, folglich mit Causalität, begabt denkt, als wenn er sich wie ein Phänomen in der Sinnenwelt (welches er wirklich auch ist) wahrnimmt und seine Causalität äußerer Bestimmung nach Naturgesetzen unterwirft. Nun wird er bald inne, daß beides zugleich stattfinden könne, ja sogar müsse. Denn daß ein Ding in der Erscheinung (das zur Sinnenwelt gehörig) gewissen Gesetzen unterworfen ist, von welchen eben dasselbe als Ding oder Wesen an sich selbst unabhängig ist, enthält nicht den mindesten Widerspruch; daß er sich selbst aber auf diese zwiefache Art vorstellen und denken müsse, beruht, was das erste betrifft, auf dem Bewußtsein seiner selbst als durch Sinne afficirten Gegenstandes, was das zweite anlangt, auf dem Bewußtsein seiner selbst als Intelligenz, d. i. als unabhängig im Vernunftgebrauch von sinnlichen Eindrücken (mithin als zur Verstandeswelt gehörig).
Daher kommt es, daß der Mensch sich eines Willens anmaßt, der nichts auf seine Rechnung kommen läßt, was bloß zu seinen Begierden und Neigungen gehört, und dagegen Handlungen durch sich als möglich, ja gar als nothwendig denkt, die nur mit Hintansetzung aller Begierden und sinnlichen Anreizungen geschehen können. Die Causalität derselben liegt in ihm als Intelligenz und in den Gesetzen der Wirkungen und Handlungen nach Principien einer intelligibelen Welt, von der er wohl nichts weiter weiß, als daß darin lediglich die Vernunft und zwar reine, von Sinnlichkeit unabhängige Vernunft das Gesetz gebe, imgleichen da er daselbst nur als Intelligenz das eigentliche Selbst (als Mensch hingegen nur Erscheinung seiner selbst) ist, jene Gesetze ihn unmittelbar und kategorisch angehen, so daß, wozu Neigungen und Antriebe (mithin die ganze Natur der Sinnenwelt) anreizen, den Gesetzen seines Wollens als Intelligenz
458 keinen Abbruch thun kann, so gar, daß er die erstere nicht verantwortet und seinem eigentlichen Selbst, d. i. seinem Willen, nicht zuschreibt, wohl aber die Nachsicht, die er gegen sie tragen möchte, wenn er ihnen zum Nachtheil der Vernunftgesetze des Willens Einfluß auf seine Maximen einräumte.
Dadurch, daß die praktische Vernunft sich in eine Verstandeswelt hinein denkt, überschreitet sie gar nicht ihre Grenzen, wohl aber wenn sie sich hineinschauen, hineinempfinden wollte. Jenes ist nur ein negativer Gedanke in Ansehung der Sinnenwelt, die der Vernunft in Bestimmung des Willens keine Gesetze giebt, und nur in diesem einzigen Punkte positiv, daß jene Freiheit als negative Bestimmung zugleich mit einem (positiven) Vermögen und sogar mit einer Causalität der Vernunft verbunden sei, welche wir einen Willen nennen, so zu handeln, daß das Princip der Handlungen der wesentlichen Beschaffenheit einer Vernunftursache, d. i. der Bedingung der Allgemeingültigkeit der Maxime als eines Gesetzes, gemäß sei. Würde sie aber noch ein Object des Willens, d. i. eine Bewegursache, aus der Verstandeswelt herholen, so überschritte sie ihre Grenzen und maßte sich an, etwas zu kennen, wovon sie nichts weiß. Der Begriff einer Verstandeswelt ist also nur ein Standpunkt, den die Vernunft sich genöthigt sieht, außer den Erscheinungen zu nehmen, um sich selbst als praktisch zu denken, welches, wenn die Einflüsse der Sinnlichkeit für den Menschen bestimmend wären, nicht möglich sein würde, welches aber doch nothwendig ist, wofern ihm nicht das Bewußtsein seiner selbst als Intelligenz, mithin als vernünftige und durch Vernunft thätige, d. i. frei wirkende, Ursache abgesprochen werden soll. Dieser Gedanke führt freilich die Idee einer anderen Ordnung und Gesetzgebung, als die des Naturmechanismus, der die Sinnenwelt trifft, herbei und macht den Begriff einer intelligibelen Welt (d. i. das Ganze vernünftiger Wesen, als Dinge an sich selbst) nothwendig, aber ohne die mindeste Anmaßung, hier weiter als bloß ihrer formalen Bedingung nach, d. i. der Allgemeinheit der Maxime des Willens als Gesetz, mithin der Autonomie des letzteren, die allein mit der Freiheit desselben bestehen kann, gemäß zu denken; da hingegen alle Gesetze, die auf ein Object bestimmt sind, Heteronomie geben, die nur an Naturgesetzen angetroffen werden und auch nur die Sinnenwelt treffen kann.
Aber alsdann würde die Vernunft alle ihre Grenze überschreiten, wenn sie es sich zu erklären unterfinge, wie reine Vernunft praktisch sein
459 könne, welches völlig einerlei mit der Aufgabe sein würde, zu erklären, wie Freiheit möglich sei.
Denn wir können nichts erklären, als was wir auf Gesetze zurückführen können, deren Gegenstand in irgend einer möglichen Erfahrung gegeben werden kann. Freiheit aber ist eine bloße Idee, deren objective Realität auf keine Weise nach Naturgesetzen, mithin auch nicht in irgend einer möglichen Erfahrung dargethan werden kann, die also darum, weil ihr selbst niemals nach irgend einer Analogie ein Beispiel untergelegt werden mag, niemals begriffen, oder auch nur eingesehen werden kann. Sie gilt nur als nothwendige Voraussetzung der Vernunft in einem Wesen, das sich eines Willens, d. i. eines vom bloßen Begehrungsvermögen noch verschiedenen Vermögens, (nämlich sich zum Handeln als Intelligenz, mithin nach Gesetzen der Vernunft unabhängig von Naturinstincten zu bestimmen) bewußt zu sein glaubt. Wo aber Bestimmung nach Naturgesetzen aufhört, da hört auch alle Erklärung auf, und es bleibt nichts übrig als Vertheidigung, d. i. Abtreibung der Einwürfe derer, die tiefer in das Wesen der Dinge geschaut zu haben vorgeben und darum die Freiheit dreust für unmöglich erklären. Man kann ihnen nur zeigen, daß der vermeintlich von ihnen darin entdeckte Widerspruch nirgend anders liege als darin, daß sie, um das Naturgesetz in Ansehung menschlicher Handlungen geltend zu machen, den Menschen nothwendig als Erscheinung betrachten mußten und nun, da man von ihnen fordert, daß sie ihn als Intelligenz auch als Ding an sich selbst denken sollten, sie ihn immer auch da noch als Erscheinung betrachten, wo denn freilich die Absonderung seiner Causalität (d. i. seines Willens) von allen Naturgesetzen der Sinnenwelt in einem und demselben Subjecte im Widerspruche stehen würde, welcher aber wegfällt, wenn sie sich besinnen und wie billig eingestehen wollten, daß hinter den Erscheinungen doch die Sachen an sich selbst (obzwar verborgen) zum Grunde liegen müssen, von deren Wirkungsgesetzen man nicht verlangen kann, daß sie mit denen einerlei sein sollten, unter denen ihre Erscheinungen stehen.
Die subjective Unmöglichkeit, die Freiheit des Willens zu erklären, ist mit der Unmöglichkeit, ein Interesse *) ausfindig und begreiflich zu
*) Interesse ist das, wodurch Vernunft praktisch, d. i. eine den Willen bestimmende Ursache, wird. Daher sagt man nur von einem vernünftigen Wesen, daß es woran ein Interesse nehme, vernunftlose Geschöpfe fühlen nur sinnliche Antriebe. Ein unmittelbares Interesse nimmt die Vernunft nur alsdann an der Handlung, wenn die Allgemeingültigkeit der Maxime derselben ein gnugsamer Bestimmungsgrund des Willens ist. Ein solches Interesse ist allein rein. Wenn sie aber den Willen nur vermittelst eines anderen Objects des Begehrens, oder unter Voraussetzung eines besonderen Gefühls des Subjects bestimmen kann, so nimmt die Vernunft nur ein mittelbares Interesse an der Handlung, und da Vernunft für sich allein weder Objecte des Willens, noch ein besonderes ihm zu Grunde liegendes Gefühl ohne Erfahrung ausfindig machen kann, so würde das letztere Interesse nur empirisch und kein reines Vernunftinteresse sein. Das logische Interesse der Vernunft (ihre Einsichten zu befördern) ist niemals unmittelbar, sondern setzt Absichten ihres Gebrauchs voraus.
460 machen, welches der Mensch an moralischen Gesetzen nehmen könne, einerlei; und gleichwohl nimmt er wirklich daran ein Interesse, wozu wir die Grundlage in uns das moralische Gefühl nennen, welches fälschlich für das Richtmaß unserer sittlichen Beurtheilung von einigen ausgegeben worden, da es vielmehr als die subjective Wirkung, die das Gesetz auf den Willen ausübt, angesehen werden muß, wozu Vernunft allein die objectiven Gründe hergiebt.
Um das zu wollen, wozu die Vernunft allein dem sinnlich-afficirten vernünftigen Wesen das Sollen vorschreibt, dazu gehört freilich ein Vermögen der Vernunft, ein Gefühl der Lust oder des Wohlgefallens an der Erfüllung der Pflicht einzuflößen, mithin eine Causalität derselben, die Sinnlichkeit ihren Principien gemäß zu bestimmen. Es ist aber gänzlich unmöglich, einzusehen, d. i. a priori begreiflich zu machen, wie ein bloßer Gedanke, der selbst nichts Sinnliches in sich enthält, eine Empfindung der Lust oder Unlust hervorbringe; denn das ist eine besondere Art von Causalität, von der wie von aller Causalität wir gar nichts a priori bestimmen können, sondern darum allein die Erfahrung befragen müssen. Da diese aber kein Verhältniß der Ursache zur Wirkung, als zwischen zwei Gegenständen der Erfahrung an die Hand geben kann, hier aber reine Vernunft durch bloße Ideen (die gar keinen Gegenstand für Erfahrung abgeben) die Ursache von einer Wirkung, die freilich in der Erfahrung liegt, sein soll, so ist die Erklärung, wie und warum uns die Allgemeinheit der Maxime als Gesetzes, mithin die Sittlichkeit interessire, uns Menschen gänzlich unmöglich. So viel ist nur gewiß: daß es nicht darum für uns Gültigkeit hat, weil es interessirt (denn das ist Heteronomie und Abhängigkeit der praktischen Vernunft von Sinnlichkeit, nämlich
461 einem zum Grunde liegenden Gefühl, wobei sie niemals sittlich gesetzgebend sein könnte), sondern daß es interessirt, weil es für uns als Menschen gilt, da es aus unserem Willen als Intelligenz, mithin aus unserem eigentlichen Selbst entsprungen ist; was aber zur bloßen Erscheinung gehört, wird von der Vernunft nothwendig der Beschaffenheit der Sache an sich selbst untergeordnet.
Die Frage also, wie ein kategorischer Imperativ möglich sei, kann zwar so weit beantwortet werden, als man die einzige Voraussetzung angeben kann, unter der er allein möglich ist, nämlich die Idee der Freiheit, imgleichen als man die Nothwendigkeit dieser Voraussetzung einsehen kann, welches zum praktischen Gebrauche der Vernunft, d. i. zur Überzeugung von der Gültigkeit dieses Imperativs, mithin auch des sittlichen Gesetzes hinreichend ist, aber wie diese Voraussetzung selbst möglich sei, läßt sich durch keine menschliche Vernunft jemals einsehen. Unter Voraussetzung der Freiheit des Willens einer Intelligenz aber ist die Autonomie desselben, als die formale Bedingung, unter der er allein bestimmt werden kann, eine nothwendige Folge. Diese Freiheit des Willens vorauszusetzen, ist auch nicht allein (ohne in Widerspruch mit dem Princip der Naturnothwendigkeit in der Verknüpfung der Erscheinungen der Sinnenwelt zu gerathen) ganz wohl möglich (wie die speculative Philosophie zeigen kann), sondern auch sie praktisch, d. i. in der Idee, allen seinen willkürlichen Handlungen als Bedingung unterzulegen, ist einem vernünftigen Wesen, das sich seiner Causalität durch Vernunft, mithin eines Willens (der von Begierden unterschieden ist) bewußt ist, ohne weitere Bedingung nothwendig. Wie nun aber reine Vernunft ohne andere Triebfedern, die irgend woher sonst genommen sein mögen, für sich selbst praktisch sein, d. i. wie das bloße Princip der Allgemeingültigkeit aller ihrer Maximen als Gesetze (welches freilich die Form einer reinen praktischen Vernunft sein würde) ohne alle Materie (Gegenstand) des Willens, woran man zum voraus irgend ein Interesse nehmen dürfte, für sich selbst eine Triebfeder abgeben und ein Interesse, welches rein moralisch heißen würde, bewirken, oder mit anderen Worten, wie reine Vernunft praktisch sein könne, das zu erklären, dazu ist alle menschliche Vernunft gänzlich unvermögend, und alle Mühe und Arbeit, hievon Erklärung zu suchen, ist verloren.
Es ist eben dasselbe, als ob ich zu ergründen suchte, wie Freiheit selbst als Causalität eines Willens möglich sei. Denn da verlasse ich den philosophischen
462 Erklärungsgrund und habe keinen anderen. Zwar könnte ich nun in der intelligibelen Welt, die mir noch übrig bleibt, in der Welt der Intelligenzen, herumschwärmen; aber ob ich gleich davon eine Idee habe, die ihren guten Grund hat, so habe ich doch von ihr nicht die mindeste Kenntniß und kann auch zu dieser durch alle Bestrebung meines natürlichen Vernunftvermögens niemals gelangen. Sie bedeutet nur ein Etwas, das da übrig bleibt, wenn ich alles, was zur Sinnenwelt gehört, von den Bestimmungsgründen meines Willens ausgeschlossen habe, bloß um das Princip der Bewegursachen aus dem Felde der Sinnlichkeit einzuschränken, dadurch daß ich es begrenze und zeige, daß es nicht Alles in Allem in sich fasse, sondern daß außer ihm noch mehr sei; dieses Mehrere aber kenne ich nicht weiter. Von der reinen Vernunft, die dieses Ideal denkt, bleibt nach Absonderung aller Materie, d. i. Erkenntniß der Objecte, mir nichts als die Form übrig, nämlich das praktische Gesetz der Allgemeingültigkeit der Maximen und diesem gemäß die Vernunft in Beziehung auf eine reine Verstandeswelt als mögliche wirkende, d. i. als den Willen bestimmende, Ursache zu denken; die Triebfeder muß hier gänzlich fehlen; es müßte denn diese Idee einer intelligibelen Welt selbst die Triebfeder oder dasjenige sein, woran die Vernunft ursprünglich ein Interesse nähme; welches aber begreiflich zu machen gerade die Aufgabe ist, die wir nicht auflösen können.
Hier ist nun die oberste Grenze aller moralischen Nachforschung, welche aber zu bestimmen, auch schon darum von großer Wichtigkeit ist, damit die Vernunft nicht einerseits in der Sinnenwelt auf eine den Sitten schädliche Art nach der obersten Bewegursache und einem begreiflichen, aber empirischen Interesse herumsuche, andererseits aber, damit sie auch nicht in dem für sie leeren Raum transscendenter Begriffe unter dem Namen der intelligibelen Welt kraftlos ihre Flügel schwinge, ohne von der Stelle zu kommen, und sich unter Hirngespinsten verliere. Übrigens bleibt die Idee einer reinen Verstandeswelt als eines Ganzen aller Intelligenzen, wozu wir selbst als vernünftige Wesen (obgleich andererseits zugleich Glieder der Sinnenwelt) gehören, immer eine brauchbare und erlaubte Idee zum Behufe eines vernünftigen Glaubens, wenn gleich alles Wissen an der Grenze derselben ein Ende hat, um durch das herrliche Ideal eines allgemeinen Reichs der Zwecke an sich selbst (vernünftiger Wesen), zu welchem wir nur alsdann als Glieder gehören können, wenn wir uns nach Maximen der Freiheit, als ob sie Gesetze der Natur wären, sorgfältig
463 verhalten, ein lebhaftes Interesse an dem moralischen Gesetze in uns zu bewirken.
Schlußanmerkung.
Der speculative Gebrauch der Vernunft in Ansehung der Natur führt auf absolute Nothwendigkeit irgend einer obersten Ursache der Welt; der praktische Gebrauch der Vernunft in Absicht auf die Freiheit führt auch auf absolute Nothwendigkeit, aber nur der Gesetze der Handlungen eines vernünftigen Wesens als eines solchen. Nun ist es ein wesentliches Princip alles Gebrauchs unserer Vernunft, ihr Erkenntniß bis zum Bewußtsein ihrer Nothwendigkeit zu treiben (denn ohne diese wäre sie nicht Erkenntniß der Vernunft). Es ist aber auch eine eben so wesentliche Einschränkung eben derselben Vernunft, daß sie weder die Nothwendigkeit dessen, was da ist, oder was geschieht, noch dessen, was geschehen soll, einsehen kann, wenn nicht eine Bedingung, unter der es da ist oder geschieht oder geschehen soll, zum Grunde gelegt wird. Auf diese Weise aber wird durch die beständige Nachfrage nach der Bedingung die Befriedigung der Vernunft nur immer weiter aufgeschoben. Daher sucht sie rastlos das Unbedingt-Nothwendige und sieht sich genöthigt, es anzunehmen, ohne irgend ein Mittel, es sich begreiflich zu machen, glücklich gnug, wenn sie nur den Begriff ausfindig machen kann, der sich mit dieser Voraussetzung verträgt. Es ist also kein Tadel für unsere Deduction des obersten Princips der Moralität, sondern ein Vorwurf, den man der menschlichen Vernunft überhaupt machen müßte, daß sie ein unbedingtes praktisches Gesetz (dergleichen der kategorische Imperativ sein muß) seiner absoluten Nothwendigkeit nach nicht begreiflich machen kann; denn daß sie dieses nicht durch eine Bedingung, nämlich vermittelst irgend eines zum Grunde gelegten Interesse, thun will, kann ihr nicht verdacht werden, weil es alsdann kein moralisches, d. i. oberstes Gesetz der Freiheit sein würde. Und so begreifen wir zwar nicht die praktische unbedingte Nothwendigkeit des moralischen Imperativs, wir begreifen aber doch seine Unbegreiflichkeit, welches alles ist, was billigermaßen von einer Philosophie, die bis zur Grenze der menschlichen Vernunft in Principien strebt, gefordert werden kann.
Musean translation
Mouseia’s complete machine-assisted Musean translation, made directly from the German of Akademie-Ausgabe IV 385–463, with Kant’s preface, three sections, page references and author’s notes. The German transcription was corrected against the 1911 page images.
446 Third Section.
Transition from the metaphysics of morals to the critique of pure practical reason.
The concept of freedom is the key to the explanation of the autonomy of the will.
The will is a kind of causality of living beings, insofar as they are rational, and freedom would be that property of this causality by which it can be effective independently of foreign causes determining it, just as natural necessity is the property of the causality of all nonrational beings by which they are determined to activity through the influence of foreign causes.
The explanation of freedom that has been given is negative and therefore, for the purpose of seeing its essence, unfruitful; but there flows from it a positive concept of it, which is all the richer and more fruitful. Since the concept of a causality carries with it that of laws according to which something must be posited through something we call a cause, namely the consequence, freedom is therefore, though it is not a property of the will under natural laws, by no means lawless for that reason, but must rather be a causality according to immutable laws, though of a special kind; for otherwise a free will would be a thing of no account. Natural necessity was a heteronomy of efficient causes; for every effect was possible only according to the law that something else determined the efficient cause to causality; what, then, can the freedom
447 of the will be other than autonomy, that is, the property of the will to be a law to itself? But the proposition: the will is in all its actions a law to itself, designates only the principle of acting on no other maxim than one that can also have itself as a universal law for its object. But this is precisely the formula of the categorical imperative and the principle of morality: thus a free will and a will under moral laws are one and the same.
If, then, freedom of the will is presupposed, morality together with its principle follows from it by mere analysis of its concept. Yet the latter is always a synthetic proposition after all: an absolutely good will is one whose maxim can always contain itself, regarded as a universal law, within itself; for by analysis of the concept of an absolutely good will that property of the maxim cannot be found. Such synthetic propositions, however, are possible only because two cognitions are connected with each other through their connection with a third, in which they are both to be found. The positive concept of freedom brings about this third, which cannot, as in the case of physical causes, be the nature of the world of sense (in whose concept the concepts of something as cause come together in relation to something else as effect). What this third is, to which freedom points us and of which we have an idea a priori, cannot yet be indicated here straightaway, nor can the deduction of the concept of freedom be made comprehensible from pure practical reason, and with it also the possibility of a categorical imperative; but it still needs some preparation.
Freedom must be presupposed as a property of the will of all rational beings.
It is not enough that we ascribe freedom to our will, for whatever reason, if we do not also have sufficient ground to attribute the very same freedom to all rational beings. For since morality serves as a law for us only as for rational beings, it must also hold for all rational beings; and since it must be derived solely from the property of freedom, freedom must also be proved as a property of the will of all rational beings; and it is not enough to derive it from certain supposed experiences
448 of human nature (although this is also absolutely impossible and can be proved solely a priori); rather, one must prove it as belonging to the activity of rational beings endowed with a will in general. I now say: every being that can act in no other way than under the idea of freedom is, precisely for that reason, really free in a practical respect, that is, all laws that are inseparably bound up with freedom hold for it, just as if its will were also declared free in itself and validly in theoretical philosophy*). Now I assert: we must necessarily lend to every rational being that has a will also the idea of freedom, under which alone it acts. For in such a being we think a reason that is practical, that is, that has causality in regard to its objects. Now one cannot possibly think a reason that with its own consciousness received steering from elsewhere in regard to its judgments; for then the subject would ascribe the determination of its judgment not to its reason but to an impulse. It must regard itself as the author of its principles independently of foreign influences; consequently, as practical reason, or as the will of a rational being, it must be regarded by itself as free; that is, the will of such a being can be an own will only under the idea of freedom, and must therefore be attributed to all rational beings in a practical respect.
Of the interest that attaches to the ideas of morality.
We have finally traced the determinate concept of morality back to the idea of freedom; but this idea we could not prove as something real, not even in ourselves and in human nature; we
*) This route—of assuming freedom, for our purpose, only as something that rational beings merely lay at the ground in the idea for their actions—I take because I would thereby not have to make myself obliged to prove freedom also in its theoretical respect. For even if this latter is left undecided, the same laws still hold for a being that can act in no other way than under the idea of its own freedom, as would bind a being that were really free. We can therefore here relieve ourselves of the burden that presses on theory.
449 saw only that we must presuppose it if we want to think ourselves a being as rational and as endowed with consciousness of its causality in regard to actions, that is, with a will; and so we find that on the very same ground we must attribute to every being endowed with reason and will this property of determining itself to action under the idea of its freedom.
But from the presupposition of these ideas there also flowed the consciousness of a law of acting: that the subjective principles of actions, that is, maxims, must always be taken in such a way that they can also hold objectively, that is, universally, as principles, and hence can serve for our own universal legislation. But why, then, ought I to subject myself to this principle, and indeed as a rational being in general, and thereby also subject all other beings endowed with reason? I will concede that no interest drives me to this, for that would not yield a categorical imperative; but I must nevertheless necessarily take an interest in it, and see how that comes about; for this ought is properly a willing that holds under the condition for every rational being if reason in it were practical without hindrances; for beings that, like us, are still affected by sensibility as incentives of another kind, and in whom what reason would do of itself alone does not always happen, that necessity of the action is called only an ought, and the subjective necessity is distinguished from the objective.
It seems, then, as if we in the idea of freedom actually presuppose only the moral law, namely the principle of the autonomy of the will itself, and could not prove its reality and objective necessity on its own; and then we would indeed have still gained something quite considerable, in that we would have determined the authentic principle more precisely than has perhaps otherwise been done; but in regard to its validity and the practical necessity of subjecting oneself to it, we would have come no further; for to anyone who asked us why the universal validity of our maxim, as a law, must be the limiting condition of our actions, and on what we ground the worth that we attach to this way of acting, which is supposed to be so great that there can be no higher interest anywhere, and how it comes about that the human being thereby alone gains his personal worth
450 that he believes he feels, in comparison with which that of an agreeable or disagreeable state is to be counted as nothing—to that person we could give no satisfactory answer.
We do indeed find that we can take an interest in a personal quality that carries with it no interest of condition, if that quality only makes us capable of partaking of the latter, in case reason should effect the distribution of it, that is, that the mere worthiness to be happy can, even without the motive of becoming partaker of this happiness, be interesting in itself: but this judgment is in fact only the effect of the importance of moral laws that is already presupposed (if we separate ourselves by the idea of freedom from all empirical interest); but that we do separate ourselves from it, that is, regard ourselves as free in acting and yet hold ourselves subject to certain laws in order to find a worth merely in our person that could compensate us for all loss of what gives our condition a worth, and how this is possible, hence from what source the moral law binds, we cannot in this way yet see.
Here there shows itself, one must freely admit, a kind of circle from which, as it seems, there is no way out. We assume ourselves as free in the order of efficient causes in order to think ourselves under moral laws in the order of ends, and we afterwards think ourselves as subject to these laws because we have attributed freedom of the will to ourselves; for freedom and the will's own legislation are both autonomy, hence interchangeable concepts, one of which therefore just for that reason cannot be used to explain the other and to state a ground for it, but at most only in order, in a logical respect, to bring apparently different representations of one and the same object under a single concept (as different fractions of equal content under the smallest expressions).
One way out still remains to us, namely to inquire whether we do not take a different standpoint when we think ourselves through freedom as causes effective a priori than when we represent ourselves, according to our actions, as effects that we see before our eyes.
It is an observation for which no subtle reflection will be required, but of which one may assume that even the commonest understanding, though in its way, by a dark distinction
451 of the power of judgment, which he calls feeling: that all representations that come to us without our choice (such as those of the senses) make objects known to us only as they affect us, while what they may be in themselves remains unknown to us; hence that, in regard to this kind of representation, even with the most strenuous attention and distinctness that the understanding can ever add, we still attain only to cognition of appearances, never of things in themselves. As soon as this distinction has once been made (possibly merely through the noted difference between the representations that are given to us from elsewhere and in which we are passive, and those that we produce solely out of ourselves and in which we prove our activity), it follows of itself that one must concede and assume that behind the appearances there is still something else, which is not appearance, namely things in themselves; although we freely admit that, since they can never become known to us, but always only as they affect us, we cannot come closer to them and can never know what they are in themselves. This must furnish a, though crude, distinction of a world of sense from a world of the understanding, of which the former can be very different according to the diversity of sensibility in various spectators of the world, while the latter, which lies at its ground, always remains the same. Even himself, and indeed according to the cognition that the human being has of himself through inner sensation, he may not presume to know as he is in himself. For since he does not, as it were, create himself and does not obtain his concept a priori but empirically, it is natural that he can gather intelligence about himself also only through inner sense and consequently only through the appearance of his nature and the manner in which his consciousness is affected; while he must nevertheless necessarily assume something else lying at the ground of this constitution of his own subject, composed as it is of nothing but appearances, namely his I as it may be constituted in itself, and thus must count himself, in respect of mere perception and receptivity for sensations, to the world of sense, but in respect of that in him which may be pure activity (of that which comes to consciousness not through affection of the senses at all, but immediately), to the intellectual world, which, however, he does not know any further.
Such an inference must the reflecting human being draw concerning all things,
452 that may come before him; presumably it is also to be met with in the commonest understanding, which, as is well known, is very inclined to expect behind the objects of the senses always still something invisible that is active for itself, but then spoils this again by soon re-sensualizing this invisible thing, that is, by wanting to make it an object of intuition, and thereby becoming not one degree wiser.
Now the human being really finds in himself a faculty by which he distinguishes himself from all other things, indeed even from himself insofar as he is affected by objects, and that is reason. This, as pure self-activity, is even raised above the understanding in this respect: that although the latter is also self-activity and, unlike sense, does not contain merely representations that arise only when one is affected by things (hence passive), it nevertheless can produce from its activity no other concepts than those that serve merely to bring sensible representations under rules and thereby to unite them in one consciousness, without which use of sensibility it would think nothing at all; whereas reason, under the name of ideas, displays a spontaneity so pure that it thereby goes far beyond everything that sensibility can ever supply it, and proves its foremost business to consist in distinguishing the world of sense from the world of understanding, and thereby in marking out for the understanding itself its boundaries.
For this reason a rational being must regard itself as an intelligence (thus not from the side of its lower powers), as belonging not to the world of sense but to the world of understanding; hence it has two standpoints from which it can consider itself and cognize laws of the use of its powers, and consequently of all its actions: first, insofar as it belongs to the world of sense, under laws of nature (heteronomy); second, as belonging to the intelligible world, under laws that, independent of nature, are not empirical but grounded merely in reason.
As a rational, and hence as a being belonging to the intelligible world, the human being can never think the causality of his own will otherwise than under the idea of freedom; for independence from the determining causes of the world of sense (such as reason must always attribute to itself) is freedom. Now with the idea of freedom the concept of autonomy is inseparably bound up, and with this the universal principle of morality, which in the idea lies at the ground of all actions
453 of rational beings, just as the law of nature lies at the ground of all appearances.
Now the suspicion we raised above is removed, as though there were contained in our inference from freedom to autonomy, and from the latter to the moral law, a secret circle, namely that we perhaps laid the idea of freedom at the ground only for the sake of the moral law, in order to infer this afterwards again from freedom, and hence could give no ground at all for it, but only begged a principle that well-disposed souls will gladly concede, but which we could never set up as a demonstrable proposition. For now we see that, if we think ourselves as free, we transfer ourselves as members into the world of understanding and cognize the autonomy of the will together with its consequence, morality; but if we think ourselves as obliged, we consider ourselves as belonging to the world of sense and yet at the same time to the world of understanding.
How is a categorical imperative possible?
The rational being counts itself, as an intelligence, to the world of understanding, and merely as an efficient cause belonging to that world does it call its causality a will. On the other side it is nevertheless also conscious of itself as a piece of the world of sense, in which its actions are met with as mere appearances of that causality whose possibility, however, cannot be seen from that causality, which we do not know; rather, in its place those actions must be seen as determined by other appearances, namely desires and inclinations, as belonging to the world of sense. As a mere member of the world of understanding, all my actions would therefore be perfectly in accordance with the principle of the autonomy of the pure will; as a mere piece of the world of sense, they would have to be taken as wholly in accordance with the natural law of desires and inclinations, hence with the heteronomy of nature. (The former would rest on the supreme principle of morality, the latter on that of happiness.) But because the world of understanding contains the ground of the world of sense, hence also of the laws of the latter, and is therefore immediately legislating in regard to my will (which belongs wholly to the world of understanding), and thus must also be thought as such, I shall therefore, as an intelligence, although on the other side like a being belonging to
454 the world of sense, nevertheless recognize myself as subject to the law of the former, that is, of reason, which in the idea of freedom contains the law of that world, and hence to the autonomy of the will; and consequently I must regard the laws of the world of understanding as imperatives for me, and actions in accordance with this principle as duties.
And thus categorical imperatives are possible, in that the idea of freedom makes me a member of an intelligible world, whereby, if I were such alone, all my actions would always be in accordance with the autonomy of the will, but since I at the same time intuit myself as a member of the world of sense, they ought to be in accordance with it—which categorical ought presents a synthetic proposition a priori, in that to my will affected by sensible desires there is added the idea of the very same will, but belonging to the world of understanding, a pure will that is practical for itself alone, which contains the supreme condition of the former according to reason; roughly as to the intuitions of the world of sense there are added concepts of the understanding, which for themselves signify nothing but lawful form in general, and thereby make possible synthetic propositions a priori, on which all cognition of a nature rests.
The practical use of common human reason confirms the correctness of this deduction. There is no one, even the most hardened villain, if only he is otherwise accustomed to use reason, who, when examples of honesty in intentions, of steadfastness in following good maxims, of sympathy and general benevolence (and these moreover combined with great sacrifices of advantages and comforts) are set before him, does not wish that he too might be so disposed. But he cannot well bring this about in himself only because of his inclinations and impulses, while he at the same time wishes to be free of such inclinations as are burdensome to himself. He therefore proves by this that he transfers himself in thought, with a will free from impulses of sensibility, into a wholly different order of things than that of his desires in the field of sensibility, since from that wish he can expect no gratification of desires, hence no state satisfying any of his actual or otherwise conceivable inclinations (for thereby the very idea that entices this wish from him would lose its preeminence), but only a greater inner worth of his person. This better person
455 he believes himself to be, however, when he places himself at the standpoint of a member of the world of understanding, to which the idea of freedom, that is, independence from determining causes of the world of sense, involuntarily compels him, and in which he is conscious of a good will that, for his evil will as a member of the world of sense, constitutes by his own confession the law whose authority he knows by transgressing it. The moral ought is therefore his own necessary willing as a member of an intelligible world, and is thought by him as an ought only insofar as he at the same time regards himself as a member of the world of sense.
Of the extreme boundary of all practical philosophy.
All human beings think of themselves, in regard to the will, as free. Hence come all judgments about actions as such as ought to have happened, although they did not happen. Yet this freedom is no concept of experience and cannot be one either, because it always remains, although experience shows the opposite of those demands that are represented as necessary under its presupposition. On the other hand it is just as necessary that everything that happens be inevitably determined according to laws of nature, and this natural necessity is also no concept of experience, precisely because it carries with it the concept of necessity, hence a cognition a priori. But this concept of a nature is confirmed by experience and must itself be unavoidably presupposed if experience, that is, a cognition of the objects of the senses connected according to universal laws, is to be possible. Hence freedom is only an idea of reason, whose objective reality is in itself doubtful, whereas nature is a concept of the understanding, which proves its reality, and must necessarily prove it, on examples of experience.
Now although a dialectic of reason arises from this, since in regard to the will the freedom attributed to it seems to stand in contradiction with natural necessity, and at this parting of the ways reason in a speculative respect finds the path of natural necessity much more traveled and more serviceable than that of freedom: yet in a practical respect the footpath of freedom is the only one on which it is possible to make use of one's reason in our doing and omitting
456 at all; hence it will be as impossible for the subtlest philosophy as for the commonest human reason to reason freedom away. It must therefore well presuppose that no true contradiction will be met with between freedom and natural necessity in the very same human actions, for it can give up the concept of nature just as little as that of freedom.
Meanwhile this seeming contradiction must at least be destroyed in a convincing manner, even if one could never comprehend how freedom is possible. For if even the thought of freedom contradicted itself, or contradicted nature, which is equally necessary, then freedom would have to be wholly abandoned in the face of natural necessity.
But it is impossible to escape this contradiction if the subject that deems itself free thinks itself in the same sense, or in the very same relation, when it calls itself free, as when it assumes itself, in regard to the very same action, to be subject to the law of nature. Hence it is an inexorable task of speculative philosophy at least to show that its illusion about this contradiction rests on this, that we think the human being in another sense and relation when we call him free than when we hold him to be a piece of nature subject to its laws, and that both can not only very well coexist, but must also be thought as necessarily united in the same subject, because otherwise no ground could be given why we should burden reason with an idea that, although it can be united without contradiction with another sufficiently attested one, nevertheless entangles us in a business by which reason is much pressed hard in its theoretical use. But this duty falls merely to speculative philosophy, so that it may clear a free path for the practical. It is therefore not left to the philosopher's discretion whether he will remove the apparent conflict or leave it untouched; for in the latter case the theory about it is a bonum vacans, into possession of which the fatalist can with good reason put himself and drive all morality out of its supposed property held without title.
Yet one cannot here say that the boundary of practical philosophy begins. For that settlement of the dispute does not belong to it at all; it demands only of speculative reason that the latter settle the discord in which it entangles itself in theoretical questions,
457 to an end, so that practical reason may have rest and security against external attacks that could dispute the ground on which it wants to build.
But the rightful claim even of common human reason to freedom of the will is grounded on the consciousness and the conceded presupposition of the independence of reason from merely subjectively determining causes, which altogether make up what belongs merely to sensation, hence under the general designation of sensibility. The human being who regards himself in this way as an intelligence thereby places himself in another order of things and in a relation to determining grounds of a wholly different kind when he thinks himself as an intelligence endowed with a will, and hence with causality, than when he perceives himself as a phenomenon in the world of sense (which he truly also is) and subjects his causality to external determination according to laws of nature. Now he soon becomes aware that both can take place at the same time, indeed must. For that a thing in appearance (as belonging to the world of sense) is subject to certain laws, of which the very same thing as thing or being in itself is independent, contains not the least contradiction; that he must, however, represent and think himself in this twofold manner rests, as regards the first, on the consciousness of himself as an object affected through the senses, and as regards the second, on the consciousness of himself as an intelligence, that is, as independent in the use of reason from sensible impressions (hence as belonging to the world of understanding).
Hence it comes about that the human being arrogates to himself a will that lets nothing count on its account that belongs merely to his desires and inclinations, and on the other hand thinks of actions as possible through himself, indeed even as necessary, which can happen only by setting aside all desires and sensible incitements. The causality of these lies in him as an intelligence, and in the laws of effects and actions according to principles of an intelligible world, of which he indeed knows nothing further than that in it reason alone, and indeed pure reason independent of sensibility, gives the law; and likewise, since there he is as an intelligence the proper self (as a human being, by contrast, only an appearance of himself), those laws concern him immediately and categorically, so that what desires and impulses (hence the whole nature of the world of sense) incite to can never be contrary to the laws of his willing as an intelligence
458 do any harm, so much so that he does not answer for the former and does not ascribe it to his proper self, that is, to his will, though he does ascribe to it the indulgence he would like to bear toward them if he granted them influence on his maxims to the detriment of the rational laws of the will.
In that practical reason thinks itself into a world of understanding, it does not at all overstep its boundaries, but it does if it wanted to look into it or feel its way into it. The former is only a negative thought in regard to the world of sense, which gives reason no laws in determining the will, and is positive only in this single point, that that freedom as a negative determination is at the same time bound up with a (positive) power and even with a causality of reason, which we call a will, so to act that the principle of actions be in accordance with the essential constitution of a rational cause, that is, with the condition of the universal validity of the maxim as a law. But if it wanted to fetch from the world of understanding even an object of the will, that is, a moving cause, it would overstep its boundaries and presume to know something of which it knows nothing. The concept of a world of understanding is therefore only a standpoint that reason sees itself compelled to take outside the appearances in order to think itself as practical—which would not be possible if the influences of sensibility were determining for the human being, but which is nevertheless necessary unless one is to deny him the consciousness of himself as an intelligence, hence as a rational cause acting through reason, that is, as freely effective. This thought indeed brings with it the idea of another order and legislation than that of the mechanism of nature, which affects the world of sense, and makes necessary the concept of an intelligible world (that is, the whole of rational beings as things in themselves), but without the least presumption of thinking anything more here than according to its formal condition, that is, the universality of the maxim of the will as a law, hence the autonomy of the latter, which alone can consist with its freedom; whereas all laws that are determined to an object give heteronomy, which is met with only in laws of nature and can also affect only the world of sense.
But then reason would overstep all its bounds if it undertook to explain how pure reason can be practical,
459 which would be wholly the same as the task of explaining how freedom is possible.
For we can explain nothing except what we can trace back to laws whose object can be given in some possible experience. Freedom, however, is a mere idea, whose objective reality can in no way be demonstrated according to laws of nature, and hence not in any possible experience either; and therefore, because no example can ever be subsumed under it by any analogy, it can never be comprehended, nor even merely seen into. It holds only as a necessary presupposition of reason in a being that believes itself conscious of a will, that is, of a power still distinct from the mere faculty of desire (namely of determining itself to action as an intelligence, hence according to laws of reason independently of natural instincts). But where determination according to laws of nature ceases, there too all explanation ceases, and nothing remains but defense, that is, the driving off of the objections of those who claim to have looked deeper into the essence of things and therefore boldly declare freedom to be impossible. One can only show them that the contradiction they supposedly discovered in it lies nowhere else than in this, that in order to make the law of nature valid in regard to human actions they had to regard the human being necessarily as appearance; and now, when it is demanded of them that they should think him as an intelligence also as a thing in itself, they still always regard him even there as appearance—where then, to be sure, the separation of his causality (that is, of his will) from all laws of nature of the world of sense would stand in contradiction in one and the same subject; but this contradiction falls away if they would bethink themselves and, as is fair, admit that behind the appearances the things in themselves must after all (though hidden) lie at the ground, of whose laws of effect one cannot demand that they should be one and the same with those under which their appearances stand.
The subjective impossibility of explaining the freedom of the will is of a piece with the impossibility of discovering and making comprehensible an interest *)
*) Interest is that through which reason becomes practical, that is, becomes a cause determining the will. Hence one says only of a rational being that it takes an interest in something; nonrational creatures feel only sensible impulses. An immediate interest reason takes in an action only when the universal validity of its maxim is a sufficient determining ground of the will. Such an interest alone is pure. But if reason can determine the will only by means of another object of desire, or under the presupposition of a particular feeling of the subject, then reason takes only a mediate interest in the action; and since reason by itself alone can discover neither objects of the will nor a particular feeling lying at its ground without experience, the latter interest would be only empirical and no pure interest of reason. The logical interest of reason (to further its insights) is never immediate, but presupposes aims of its use.
460 which the human being can take in moral laws, is one and the same; and yet he really does take an interest in them, for which we call the foundation in us moral feeling, which some have falsely put forward as the standard of our moral judgment, whereas it must rather be regarded as the subjective effect that the law exercises on the will, to which reason alone supplies the objective grounds.
To will what reason alone prescribes as an ought to the sensibly affected rational being, there is indeed required a power of reason to infuse a feeling of pleasure or of satisfaction in the fulfillment of duty, hence a causality of reason to determine sensibility in accordance with its principles. But it is wholly impossible to see, that is, to make comprehensible a priori, how a mere thought that itself contains nothing sensible produces a sensation of pleasure or displeasure; for that is a special kind of causality, of which, as of all causality, we can determine nothing a priori, but must therefore alone consult experience. But since experience can supply no relation of cause to effect other than between two objects of experience, and here pure reason is supposed, through mere ideas (which yield no object for experience), to be the cause of an effect that indeed lies in experience, the explanation of how and why the universality of the maxim as a law, hence morality, interests us is wholly impossible for us human beings. This much only is certain: that it does not have validity for us because it interests (for that would be heteronomy and dependence of practical reason on sensibility, namely
461 on a feeling lying at its ground, in which case it could never be morally legislating), but that it interests because it holds for us as human beings, since it has sprung from our will as intelligence, hence from our proper self; but what belongs to mere appearance is necessarily subordinated by reason to the constitution of the thing in itself.
The question, then, how a categorical imperative is possible, can indeed be answered so far as one can state the sole presupposition under which it alone is possible, namely the idea of freedom, and likewise so far as one can see the necessity of this presupposition, which is sufficient for the practical use of reason, that is, for conviction of the validity of this imperative, and hence also of the moral law; but how this presupposition itself is possible can never be seen through by any human reason. But under the presupposition of the freedom of the will of an intelligence, the autonomy of that will, as the formal condition under which alone it can be determined, is a necessary consequence. To presuppose this freedom of the will is also not only quite possible (without falling into contradiction with the principle of natural necessity in the connection of the appearances of the world of sense), as speculative philosophy can show, but it is also necessary without further condition for a rational being that is conscious of its causality through reason, hence of a will (which is distinct from desires), to lay it practically, that is, in the idea, at the ground of all its arbitrary actions. But how pure reason can be practical for itself without other incentives that may be taken from anywhere else, that is, how the mere principle of the universal validity of all its maxims as laws (which would indeed be the form of a pure practical reason), without any matter (object) of the will in which one might beforehand take some interest, can for itself furnish an incentive and bring about an interest that would be called purely moral, or in other words, how pure reason can be practical—to explain this, all human reason is wholly incapable, and all effort and labor spent in seeking an explanation of it is lost.
It is just the same as if I sought to fathom how freedom itself as the causality of a will is possible. For there I leave the philosophical
462 ground of explanation and have no other. I could indeed now rove about in the intelligible world that still remains to me, in the world of intelligences; but although I have an idea of it that has its good ground, I nevertheless have not the least cognition of it, and can never attain to such cognition through all the striving of my natural faculty of reason. It signifies only a something that remains when I have excluded everything belonging to the world of sense from the determining grounds of my will, merely in order to limit the principle of moving causes to the field of sensibility, by bounding it and showing that it does not comprehend everything in everything, but that beyond it there is still more; but I know nothing further of this more. Of pure reason, which thinks this ideal, there remains for me after separating off all matter, that is, cognition of objects, nothing but the form, namely the practical law of the universal validity of maxims, and in accordance with it, to think reason in relation to a pure world of understanding as a possible efficient cause, that is, as a cause determining the will; the incentive must here be wholly absent, unless this very idea of an intelligible world were itself the incentive, or that in which reason originally took an interest; but to make this comprehensible is precisely the task we cannot solve.
Here, then, is the supreme boundary of all moral inquiry, which is of great importance to determine also for this reason: that reason may not, on the one hand, in the world of sense, search about in a manner harmful to morals for the supreme moving cause and for a comprehensible but empirical interest, and, on the other hand, that it may not in the space of transcendent concepts, empty for it, under the name of the intelligible world, beat its wings powerlessly without getting from the spot, and lose itself among figments. For the rest, the idea of a pure world of understanding as a whole of all intelligences, to which we ourselves belong as rational beings (though on the other side at the same time as members of the world of sense), always remains a serviceable and permitted idea for the purpose of a rational faith, even though all knowledge comes to an end at its boundary, in order, through the glorious ideal of a universal realm of ends in themselves (of rational beings), to which we can belong as members only when we carefully
463 conduct ourselves according to maxims of freedom as if they were laws of nature, and to bring about a lively interest in the moral law within us.
Concluding remark.
The speculative use of reason in regard to nature leads to the absolute necessity of some supreme cause of the world; the practical use of reason with a view to freedom leads also to absolute necessity, but only of the laws of the actions of a rational being as such. Now it is an essential principle of all use of our reason to drive its cognition to the consciousness of its necessity (for without this it would not be cognition of reason). But it is also an equally essential limitation of the very same reason that it can see the necessity neither of what is or happens, nor of what ought to happen, unless a condition under which it is or happens or ought to happen is laid at the ground. But in this way the satisfaction of reason is only ever further postponed by the constant inquiry after the condition. Hence it restlessly seeks the unconditionally necessary and sees itself compelled to assume it, without any means of making it comprehensible to itself, happy enough if only it can find out the concept that can be reconciled with this presupposition. It is therefore no censure of our deduction of the supreme principle of morality, but a reproach that one would have to make to human reason in general, that it cannot make an unconditioned practical law (such as the categorical imperative must be) comprehensible in its absolute necessity; for that it will not do this by means of a condition, namely by means of some interest laid at the ground, cannot be held against it, because then it would not be a moral law, that is, a supreme law of freedom. And so we do indeed not comprehend the practical unconditional necessity of the moral imperative, but we do comprehend its incomprehensibility, which is all that can fairly be demanded of a philosophy that strives in principles up to the boundary of human reason.
Plain English translation
Mouseia’s complete machine-assisted Plain English translation, made independently and directly from the same German, with every section, page reference and author’s note.
446 Third Section
Transition from the Metaphysics of Morals to the Critique of Pure Practical Reason
The concept of freedom is the key to explaining the autonomy of the will.
The will is a kind of causality that living beings have insofar as they are rational. Freedom would be the property of this causality that allows it to act independently of outside causes that determine it. In contrast, natural necessity is the property of the causality of all nonrational beings by which outside causes determine them to act.
This explanation of freedom is negative. It therefore does not help us understand what freedom is in itself. But it leads to a positive concept of freedom that is all the richer and more fruitful. The concept of causality includes that of laws: through something we call a cause, something else, its effect, must be brought about according to these laws. So although freedom is not a property of the will under laws of nature, it is not lawless. Instead, it must be a causality governed by unchanging laws, though laws of a special kind. Otherwise a free will would be an impossibility. Natural necessity was a heteronomy of acting causes. For every effect was possible only under the law that something else determined the acting cause to exercise its causality. What else, then, can freedom
447 of the will be but autonomy—that is, the will's property of being a law to itself? But the statement that the will is a law to itself in all its actions expresses only this principle: act on no maxim except one that can also have itself, as a universal law, as its object. This is precisely the formula of the categorical imperative and the principle of morality. A free will and a will under moral laws are therefore one and the same.
If freedom of the will is assumed, then morality and its principle follow simply by analyzing the concept of freedom. Still, the latter principle remains a synthetic proposition: an absolutely good will is one whose maxim can always contain itself when considered as a universal law. For this property of the maxim cannot be found by analyzing the concept of an absolutely good will. Such synthetic propositions are possible only when the two items of knowledge are connected through their connection with a third, in which both can be found. The positive concept of freedom provides this third thing. It cannot be the nature of the world of sense, as it can be with physical causes. (The concept of that nature brings together the concepts of something as a cause and of something else as its effect.) We cannot yet say here what this third thing is, to which freedom points us and of which we have an a priori idea. Nor can we yet make the derivation of the concept of freedom from pure practical reason intelligible, and with it the possibility of a categorical imperative. This still requires some preparation.
Freedom must be assumed as a property of the will of all rational beings.
It is not enough to attribute freedom to our will, whatever our reason for doing so, unless we have sufficient grounds for attributing the very same freedom to all rational beings. Morality serves as a law for us only because we are rational beings. It must therefore hold for all rational beings as well. And since it must be derived solely from the property of freedom, freedom must also be proved to be a property of the will of all rational beings. It is not enough to establish it from certain supposed experiences
448 of human nature. (In fact, that is completely impossible: it can be established only a priori.) Instead, we must prove that freedom belongs to the activity of rational beings endowed with a will as such. I now say this: any being that cannot act except under the idea of freedom is, for that very reason, actually free in a practical respect. That is, all the laws inseparably connected with freedom hold for it, just as if its will had also been validly declared free in itself in theoretical philosophy.*) I further claim that we must necessarily give every rational being that has a will the idea of freedom, under which alone it acts. For in such a being we think of a reason that is practical—that is, that has causality in relation to its objects. But we cannot possibly think of a reason that is conscious of receiving direction for its judgments from somewhere else. In that case, the subject would attribute the determination of its judgment to an impulse, not to its reason. Reason must see itself as the source of its principles, independent of outside influences. So, as practical reason, or as the will of a rational being, it must regard itself as free. In other words, this being's will can be a will of its own only under the idea of freedom. For practical purposes, we must therefore attribute freedom to all rational beings.
On the interest attached to the ideas of morality
We have finally traced the definite concept of morality back to the idea of freedom. Yet we could not prove that freedom is something real, even in ourselves and in human nature. We
*) I take this approach—accepting freedom as sufficient for our purpose when rational beings merely base their actions on it as an idea—so that I need not undertake to prove freedom from a theoretical standpoint as well. Even if that theoretical question remains unsettled, the same laws hold for a being that cannot act except under the idea of its own freedom as would bind a being that really was free. Here, then, we can free ourselves from the burden that weighs on theory.
449 saw only that we must assume freedom if we are to think of a being as rational and as conscious of its causality in relation to actions—that is, as endowed with a will. We thus find that, on precisely the same grounds, we must attribute this property to every being endowed with reason and will: it determines itself to act under the idea of its freedom.
But assuming these ideas also led to awareness of a law for acting: the subjective principles of actions, or maxims, must always be taken in such a way that they can also hold objectively—that is, universally—as principles. They can therefore serve for our own universal lawgiving. But why should I submit to this principle, and do so as a rational being as such, so that all other beings endowed with reason must do so too? I will grant that no interest drives me to do this, since that would not yield a categorical imperative. But I must still necessarily take an interest in it and understand how this happens. For this “ought” is really a willing that holds for every rational being on the condition that its reason is practical without obstacles. Beings like us are also affected by sensibility, which supplies motives of another kind. In us, what reason alone would do does not always happen. So for us, this necessity of action is called only an “ought,” and subjective necessity is distinguished from objective necessity.
It therefore seems that, in the idea of freedom, we have really only assumed the moral law itself, namely the principle of autonomy of the will. We seem unable to prove its reality and objective necessity on their own. We would still have gained something quite substantial: at least we would have defined the genuine principle more precisely than is usually done. But we would have made no progress on its validity or on the practical necessity of submitting to it. Suppose someone asked us why the universal validity of our maxim as a law must be the condition that limits our actions. Suppose they asked what grounds the value we give to this way of acting—a value said to be so great that there can be no higher interest at all—and how it happens that a person believes this alone lets them feel their personal worth,
450 beside which the value of a pleasant or unpleasant condition counts for nothing. We could give no satisfactory answer.
We do find that we can take an interest in a personal quality that brings no interest in our condition with it, provided this quality makes us fit to share in that condition if reason were to distribute it. In other words, simply being worthy of happiness can interest us in itself, even without the motive of obtaining that happiness. But this judgment is really only an effect of the importance already assumed for moral laws, when we use the idea of freedom to separate ourselves from every empirical interest. We still cannot understand in this way why we should separate ourselves from that interest—that is, regard ourselves as free in acting—and yet hold ourselves subject to certain laws, in order to find a value merely in our person that could compensate us for the loss of everything that gives our condition a value. We thus still cannot understand how this is possible, and hence what makes the moral law binding.
We must freely admit that a kind of circle appears here, from which there seems to be no escape. We assume we are free in the order of acting causes so that we can think of ourselves as under moral laws in the order of ends. We then think of ourselves as subject to these laws because we have attributed freedom of the will to ourselves. For freedom and the will's own lawgiving are both autonomy, and so are interchangeable concepts. For that very reason, neither can be used to explain the other or give its ground. At most, they can be used for a logical purpose: to bring apparently different representations of the same object under a single concept, as different fractions with the same value are reduced to their simplest expressions.
But one way out remains. We can ask whether we take a different standpoint when we think of ourselves, through freedom, as causes that act a priori, from the standpoint we take when we picture ourselves through our actions as effects that we see before our eyes.
There is an observation that requires no subtle thinking. We can assume that even the most ordinary understanding can make it, though in its own way through an obscure distinction
451 made by its judgment, which it calls feeling. The observation is this: all representations that come to us without our choosing them, such as those of the senses, let us know objects only as they affect us. What the objects may be in themselves remains unknown to us. So with this kind of representation, even the greatest attention and clarity that the understanding can add let us know only appearances, never things in themselves. Once this distinction is made, something else follows on its own. Behind appearances we must admit and assume something else that is not appearance, namely things in themselves. We can draw the distinction, if only by noticing the difference between representations given to us from elsewhere, in which we are passive, and those we produce entirely from ourselves, in which we show our activity. At the same time, we freely acknowledge a limit: since we can never know these things, but only how they affect us, we cannot get any closer to them or ever know what they are in themselves. This must yield a distinction, though a rough one, between a world of sense and a world of understanding. The first can differ greatly with differences in the sensibility of the various observers of the world. The second, which underlies it, always remains the same. Even in knowing themselves through inner sensation, human beings must not claim to know themselves as they are in themselves. For people do not, so to speak, create themselves. They acquire their concept of themselves empirically, not a priori. So it is natural that they can learn about themselves only through inner sense, and thus only through the appearance of their nature and the way their consciousness is affected. Yet they must necessarily assume something else that underlies this character of their own subject, composed entirely of appearances: their self, as it may be in itself. So in respect of merely perceiving sensations and being receptive to them, they must count themselves as belonging to the world of sense. But in respect of whatever may be pure activity in them—whatever reaches consciousness directly, not through the senses being affected—they must count themselves as belonging to the intellectual world, which they nevertheless know no further.
A thinking person must reach this kind of conclusion about all the things
452 that may appear to them. The conclusion is probably also found in the most ordinary understanding. As we know, it is very inclined to expect something invisible, active on its own, behind the objects of the senses. But it spoils this by soon trying to give this invisible thing a sensory form again—that is, to make it an object of intuition. In this way it becomes no wiser at all.
Now people do actually find in themselves a capacity that distinguishes them from all other things, and even from themselves insofar as objects affect them. This capacity is reason. As pure activity of its own, reason is raised even above the understanding in the following way. Understanding, too, is activity of its own. Unlike sense, it does not merely contain representations that arise only when things affect us and we are therefore passive. Still, its activity can produce no concepts except those that serve to bring sensory representations under rules and so unite them in one consciousness. Without this use of sensibility it would think nothing at all. Reason, in contrast, displays such pure spontaneity in what are called ideas that it goes far beyond anything sensibility can supply. It shows its main work in distinguishing the world of sense from the world of understanding, and in this way setting limits for the understanding itself.
For this reason, a rational being must regard itself, as an intelligence and thus not from the side of its lower powers, as belonging to the world of understanding, not the world of sense. It therefore has two standpoints from which it can consider itself and know laws for using its powers, and thus for all its actions. First, insofar as it belongs to the world of sense, it is under laws of nature: heteronomy. Second, as belonging to the intelligible world, it is under laws that are independent of nature and based not on experience but on reason alone.
As a rational being, and thus one belonging to the intelligible world, a human being can think of the causality of their own will only under the idea of freedom. For independence from the determining causes of the world of sense—an independence reason must always attribute to itself—is freedom. Now the concept of autonomy is inseparably connected with the idea of freedom. With autonomy, in turn, is connected the universal principle of morality. In the idea, this principle underlies all the actions
453 of rational beings, just as the law of nature underlies all appearances.
We can now remove the suspicion we raised above: that there might be a hidden circle in our inference from freedom to autonomy and from autonomy to the moral law. The suspicion was that we might have made the idea of freedom our starting point only for the sake of the moral law, in order then to infer this law from freedom in return. We would thus be unable to give any ground for the law. We would only be asking to have a principle granted to us. Well-disposed people might gladly grant it, but we could never put it forward as a provable proposition. For we now see that when we think of ourselves as free, we place ourselves in the world of understanding as its members and recognize the autonomy of the will, along with its consequence, morality. But when we think of ourselves as under obligation, we consider ourselves as belonging to the world of sense and yet also to the world of understanding.
How is a categorical imperative possible?
A rational being counts itself, as an intelligence, as belonging to the world of understanding. Only as an acting cause belonging to that world does it call its causality a will. On the other hand, it is also conscious of itself as a part of the world of sense. There its actions are found as mere appearances of that causality. But their possibility cannot be understood from this causality, which we do not know. Instead, those actions must be understood as determined by other appearances, namely desires and inclinations, and thus as belonging to the world of sense. If I were only a member of the world of understanding, all my actions would therefore agree perfectly with the principle of autonomy of the pure will. If I were only a part of the world of sense, my actions would have to be taken as agreeing entirely with the natural law of desires and inclinations, and thus with the heteronomy of nature. (The first would rest on the highest principle of morality, the second on that of happiness.) But the world of understanding contains the ground of the world of sense, and thus of its laws as well. It therefore gives laws directly to my will, which belongs entirely to the world of understanding, and must be thought of as giving laws in this way. So as an intelligence, although from the other side I am a being belonging to the
454 world of sense, I must recognize that I am subject to the law of the first world. That is, I am subject to reason, which contains that law in the idea of freedom, and so to autonomy of the will. I must therefore regard the laws of the world of understanding as imperatives for me, and actions that agree with this principle as duties.
This is how categorical imperatives are possible. The idea of freedom makes me a member of an intelligible world. If I were only that, all my actions always would agree with autonomy of the will. But since I also view myself as a member of the world of sense, they ought to agree with it. This categorical “ought” expresses a synthetic a priori proposition. For to my will as affected by sensory desires is added the idea of this very same will as pure, belonging to the world of understanding, and practical on its own. According to reason, this pure will contains the highest condition of the first will. This is roughly like the way concepts of the understanding are added to intuitions of the world of sense. These concepts by themselves mean nothing but the form of law in general. Their addition makes possible the synthetic a priori propositions on which all knowledge of a nature rests.
The practical use of ordinary human reason confirms that this derivation is correct. Take anyone, even the worst wrongdoer, as long as they are otherwise used to using reason. Show them examples of honesty in intentions, firmness in following good maxims, sympathy, and goodwill toward everyone, combined with great sacrifices of advantage and comfort. There is no one who would not wish to have that disposition too. But because of their inclinations and impulses, they cannot easily bring this about in themselves. Yet at the same time, they wish to be free of these inclinations, which are a burden even to them. This shows that, in thought, they place themselves with a will free from the impulses of sensibility in an entirely different order of things from that of their desires in the field of sensibility. For from that wish they can expect no gratification of their desires, and thus no condition that satisfies any of their actual or even conceivable inclinations. (That would rob the very idea that draws this wish from them of its superiority.) They can expect only a greater inner worth of their person. This better person
455 is what they believe themselves to be when they take the standpoint of a member of the world of understanding. The idea of freedom—that is, independence from the determining causes of the world of sense—forces them to this standpoint without their choosing it. Here they are conscious of a good will. By their own admission, this good will provides the law for their bad will as a member of the world of sense. They recognize the law's authority even while breaking it. So the moral “ought” is their own necessary willing as a member of an intelligible world. They think of it as an “ought” only insofar as they also regard themselves as a member of the world of sense.
On the outermost limit of all practical philosophy
All human beings think of themselves as free in respect of their will. This is the source of all judgments about actions that ought to have happened, even though they did not happen. Yet this freedom is not a concept drawn from experience, nor can it be. For it always remains, even when experience shows the opposite of the requirements presented as necessary on the assumption of freedom. On the other hand, it is just as necessary that everything that happens be inevitably determined by laws of nature. This natural necessity is not a concept drawn from experience either, precisely because it includes the concept of necessity, and thus of a priori knowledge. But experience confirms this concept of a nature. It must itself inevitably be assumed if experience is to be possible—that is, knowledge of objects of the senses connected according to universal laws. Freedom is therefore only an idea of reason, whose objective reality is in itself doubtful. Nature, however, is a concept of the understanding that proves its reality in examples from experience, and must necessarily do so.
This gives rise to a dialectic of reason. The freedom attributed to the will seems to contradict natural necessity. At this crossroads, reason finds the path of natural necessity much better cleared and more usable for speculative purposes than the path of freedom. But for practical purposes, the footpath of freedom is the only one on which we can use our reason in what we do and leave
456 undone. So it is just as impossible for the most subtle philosophy as for the most ordinary human reason to argue freedom away. Reason must therefore assume that there is no real contradiction between freedom and the natural necessity of the very same human actions. For it can give up the concept of nature no more than it can give up the concept of freedom.
Still, this apparent contradiction must at least be convincingly removed, even if we can never comprehend how freedom is possible. For if even the thought of freedom contradicts itself, or contradicts nature, which is equally necessary, freedom would have to be given up entirely in favor of natural necessity.
But we cannot escape this contradiction if the subject that thinks itself free thinks of itself in the same sense, or in exactly the same relation, when it calls itself free as when it assumes it is subject to the law of nature with respect to the very same action. Speculative philosophy therefore has an unavoidable task. It must at least show that its mistake about the contradiction rests on this: we think of a human being in a different sense and relation when we call that person free than when we regard them as part of nature and subject to its laws. It must also show that the two can not only coexist perfectly well, but must be thought of as necessarily united in the same subject. Otherwise we could give no reason for burdening reason with an idea that involves us in a task that severely restricts reason in its theoretical use—even though this idea can be combined without contradiction with another that is well established. But this duty belongs only to speculative philosophy, so that it can clear the way for practical philosophy. The philosopher therefore cannot choose whether to remove the apparent conflict or leave it untouched. In the latter case, the theory on this point is ownerless property. The fatalist can rightfully take possession of it and drive all morality out of the supposed property that it occupied without title.
But we cannot yet say that the limit of practical philosophy begins here. For settling that dispute is not its business at all. It only requires speculative reason to end the disagreement in which it entangles itself in theoretical questions,
457 so that practical reason can have peace and security against outside attacks that might challenge its claim to the ground on which it wants to build.
But even ordinary human reason's rightful claim to freedom of the will rests on the awareness and the accepted assumption that reason is independent of merely subjectively determining causes. Taken together, these causes make up what belongs merely to sensation, and thus falls under the general name of sensibility. A human being who regards themselves in this way as an intelligence thereby places themselves in a different order of things, and in relation to determining grounds of a quite different kind. This happens when they think of themselves as an intelligence endowed with a will, and thus with causality, rather than when they perceive themselves as an appearance in the world of sense—which they really are as well—and subject their causality to outside determination by laws of nature. Now they soon realize that both can, and indeed must, take place at once. There is not the slightest contradiction in a thing as an appearance, belonging to the world of sense, being subject to certain laws from which that very same thing, or being, in itself is independent. But they must represent and think of themselves in these two ways. The first is based on their awareness of themselves as an object affected through the senses. The second is based on their awareness of themselves as an intelligence: as independent of sensory impressions in their use of reason, and thus as belonging to the world of understanding.
This is why human beings claim a will that does not charge to its own account anything belonging merely to their desires and inclinations. On the other hand, they think of actions as possible through themselves, and even as necessary, that can take place only by setting aside all desires and sensory attractions. The causality of these actions lies in them as an intelligence, and in the laws of effects and actions according to principles of an intelligible world. They know nothing further about that world except that reason alone gives laws in it—specifically, pure reason, independent of sensibility. They also know that, since in that world they are their proper self only as an intelligence, while as a human being they are only an appearance of themselves, those laws concern them directly and categorically. Thus, what inclinations and impulses—and so the whole nature of the world of sense—urge them to do cannot impair the laws of their willing as an intelligence
458 —so much so that they do not hold themselves responsible for those inclinations and impulses, or attribute them to their proper self, their will. They do, however, hold themselves responsible for any indulgence they might show them by allowing them to influence their maxims at the expense of the will's laws of reason.
Practical reason does not overstep its limits at all by thinking itself into a world of understanding. But it would do so if it tried to see or feel itself into that world. The former is only a negative thought in relation to the world of sense, which gives reason no laws for determining the will. It is positive only in this one point: that freedom, as a negative determination, is also connected with a positive capacity, and even with a causality of reason. We call this a will: the capacity to act so that the principle of actions agrees with the essential character of a rational cause, that is, with the condition that the maxim be universally valid as a law. But if reason also brought an object of the will, that is, a motive, from the world of understanding, it would overstep its limits and claim to know something about which it knows nothing. The concept of a world of understanding is therefore only a standpoint that reason finds itself forced to take outside appearances in order to think of itself as practical. This would be impossible if the influences of sensibility determined human beings. Yet it is necessary unless we deny them awareness of themselves as an intelligence, and thus as a rational cause active through reason—that is, a freely acting cause. This thought does of course bring with it the idea of an order and a lawgiving different from the mechanism of nature that applies to the world of sense. It makes necessary the concept of an intelligible world: the whole of rational beings as things in themselves. But it makes no claim to think here any further than in accordance with that world's merely formal condition. This is the universality of the will's maxim as a law, and thus the will's autonomy, which alone can coexist with its freedom. In contrast, all laws directed to an object yield heteronomy, which can be found only in laws of nature and can apply only to the world of sense.
But reason would overstep all its limits if it undertook to explain how pure reason can be practical.
459 That would be exactly the same task as explaining how freedom is possible.
For we can explain only what we can trace back to laws whose object can be given in some possible experience. But freedom is a mere idea. Its objective reality cannot be established in any way through laws of nature, and so cannot be established in any possible experience. No example can ever be supplied for it by any analogy. For this reason, it can never be comprehended or even understood. It holds only as a necessary assumption of reason in a being that believes itself conscious of a will. A will is a capacity distinct from the mere capacity to desire: it is the capacity to determine oneself to act as an intelligence, and thus according to laws of reason, independently of natural instincts. But where determination by laws of nature ends, all explanation ends too. Nothing remains but defense: rejecting the objections of those who claim to have looked deeper into the nature of things and therefore confidently declare freedom impossible. We can only show them where the contradiction they think they have discovered really lies. To apply the law of nature to human actions, they had to consider a human being as an appearance. Now they are asked to think of that person, as an intelligence, also as a thing in itself, but they still consider the person an appearance. On that view, of course, separating the person's causality, or will, from all laws of nature in the world of sense would involve a contradiction in one and the same subject. But the contradiction disappears if they reflect and admit, as they should, that behind appearances there must be things in themselves as their ground, though hidden. We cannot demand that the laws of their effects be the same as the laws under which their appearances stand.
The subjective impossibility of explaining freedom of the will is the same as the impossibility of finding and making intelligible an interest *)
*) Interest is that through which reason becomes practical—that is, a cause that determines the will. This is why we say only of a rational being that it takes an interest in something. Nonrational creatures feel only sensory impulses.
Reason takes a direct interest in an action only when the universal validity of the action's maxim is a sufficient ground for determining the will. Only an interest of this kind is pure. But if reason can determine the will only through another object of desire, or on the assumption of a particular feeling in the subject, it takes only an indirect interest in the action. Reason alone cannot, without experience, find either objects of the will or a particular feeling underlying it. So this latter interest would be merely empirical, not a pure interest of reason. Reason's logical interest—in advancing its insights—is never direct. It presupposes purposes for which reason is to be used.
460 that human beings could take in moral laws. Yet they actually do take an interest in them. We call the basis for this in us moral feeling. Some have wrongly presented it as the standard for our moral judgment. Instead, it must be regarded as the subjective effect that the law has on the will. Reason alone supplies the objective grounds for this effect.
For a rational being affected by the senses to will what reason alone prescribes as what it ought to do, reason must indeed have a capacity to instill a feeling of pleasure or satisfaction in fulfilling duty. Reason must therefore have a causality that determines sensibility in accordance with its principles. But it is completely impossible to understand—that is, to make intelligible a priori—how a mere thought, which itself contains nothing sensory, produces a sensation of pleasure or displeasure. For this is a special kind of causality. As with all causality, we can determine nothing about it a priori, but must consult experience alone. Yet experience can provide a relation of cause to effect only between two objects of experience. Here, however, pure reason, through mere ideas that provide no object for experience at all, is supposed to cause an effect that does lie in experience. So it is completely impossible for us human beings to explain how and why the universality of a maxim as a law, and thus morality, interests us. Only this much is certain: it is not valid for us because it interests us (for that is heteronomy and dependence of practical reason on sensibility, namely
461 on an underlying feeling, in which case reason could never give moral laws). Instead, it interests us because it is valid for us as human beings, since it has arisen from our will as an intelligence, and thus from our proper self. But reason necessarily subordinates what belongs to mere appearance to the character of the thing in itself.
We can therefore answer the question of how a categorical imperative is possible to this extent: we can state the one assumption under which alone it is possible, namely the idea of freedom. We can also understand the necessity of this assumption. This is enough for the practical use of reason—that is, to convince us of the validity of this imperative, and thus also of the moral law. But no human reason can ever understand how this assumption itself is possible. If we assume freedom of the will of an intelligence, however, its autonomy follows necessarily, as the formal condition under which alone that will can be determined. Assuming this freedom of the will is entirely possible, as speculative philosophy can show, without contradicting the principle of natural necessity in the connection of appearances in the world of sense. But it is also unconditionally necessary for a rational being to make freedom the practical condition, as an idea, underlying all its chosen actions, if that being is conscious of its causality through reason and thus of a will distinct from desires. Yet how can pure reason be practical on its own, without other motives taken from anywhere else? How can the mere principle of the universal validity of all its maxims as laws—which would indeed be the form of a pure practical reason—provide a motive on its own and produce an interest that would be called purely moral, without any matter or object of the will in which we might take an interest in advance? In other words, how can pure reason be practical? All human reason is completely unable to explain this, and every effort and labor spent seeking an explanation is wasted.
It is just as if I tried to discover how freedom itself is possible as the causality of a will. For then I leave behind the philosophical
462 ground of explanation and have no other. I could, of course, now wander around in the intelligible world that remains to me, the world of intelligences. But although I have an idea of it that is well grounded, I do not have the slightest knowledge of it. Nor can I ever reach such knowledge through all the efforts of my natural power of reason. The idea means only a something that remains when I have excluded everything belonging to the world of sense from the grounds that determine my will. Its only purpose is to restrict the principle of motives drawn from the field of sensibility. I set a limit to that principle and show that it does not contain everything within itself: there is something more outside it. But I have no further knowledge of this something more. Once I remove all matter—that is, knowledge of objects—from the pure reason that thinks this ideal, nothing remains for me but its form. This is the practical law of the universal validity of maxims, and, in accordance with it, the thought of reason in relation to a pure world of understanding as a possible acting cause, that is, one that determines the will. Here a motive must be entirely absent, unless this idea of an intelligible world were itself the motive, or that in which reason originally took an interest. But making this intelligible is precisely the task we cannot solve.
Here, then, is the outermost limit of all moral inquiry. Defining it is already very important for two reasons. On the one hand, it keeps reason from searching around in the world of sense, in a way harmful to morality, for the highest motive and for a comprehensible but empirical interest. On the other, it keeps reason from beating its wings helplessly without moving forward in the space of transcendent concepts, empty for reason, under the name of the intelligible world, and losing itself among fantasies. Still, the idea of a pure world of understanding, as a whole of all intelligences to which we ourselves belong as rational beings—though we are also members of the world of sense from the other side—always remains a useful and permissible idea for the purpose of a rational faith, even though all knowledge ends at its boundary. Through the magnificent ideal of a universal kingdom of ends in themselves, or rational beings—a kingdom to which we can belong as members only if we carefully
463 conduct ourselves according to maxims of freedom as if they were laws of nature—this idea serves to produce in us a lively interest in the moral law.
Concluding Note
The speculative use of reason with regard to nature leads to the absolute necessity of some highest cause of the world. The practical use of reason with regard to freedom also leads to absolute necessity, but only that of the laws of action of a rational being as such. Now it is an essential principle of every use of our reason to push its knowledge to the point of being conscious of that knowledge's necessity. Without this, it would not be knowledge of reason. But it is an equally essential limitation of this same reason that it can understand neither the necessity of what exists or happens, nor that of what ought to happen, unless it takes as its basis a condition under which that thing exists, happens, or ought to happen. In this way, however, reason's constant demand for the condition only postpones its satisfaction further and further. It therefore searches tirelessly for what is unconditionally necessary and finds itself forced to assume it, without any means of making it intelligible to itself. Reason is fortunate enough if it can merely find the concept that is compatible with this assumption. So the inability to make an unconditional practical law—such as the categorical imperative must be—intelligible in its absolute necessity is not a criticism of our derivation of the highest principle of morality. It is a charge that would have to be made against human reason in general. We cannot blame reason for being unwilling to do this through a condition, namely through some interest assumed as a basis. For then the law would not be a moral law, that is, the highest law of freedom. And so, although we do not comprehend the practical, unconditional necessity of the moral imperative, we do comprehend its incomprehensibility. This is all that can reasonably be required of a philosophy that strives, in its principles, to reach the limit of human reason.
About this section
Section III is part of Groundwork of the Metaphysics of Morals by Immanuel Kant. This page sets the German original beside 2 direct-source translations, so any line can be checked against the source. It is section 4 of 4 in the work, which is kept in the European tradition.
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