Preface
Original German
385 Grundlegung zur Metaphysik der Sitten von Immanuel Kant.
387 Vorrede.
Die alte griechische Philosophie theilte sich in drei Wissenschaften ab: Die Physik, die Ethik und die Logik. Diese Eintheilung ist der Natur der Sache vollkommen angemessen, und man hat an ihr nichts zu verbessern, als etwa nur das Princip derselben hinzu zu thun, um sich auf solche Art theils ihrer Vollständigkeit zu versichern, theils die nothwendigen Unterabtheilungen richtig bestimmen zu können.
Alle Vernunfterkenntniß ist entweder material und betrachtet irgend ein Object; oder formal und beschäftigt sich bloß mit der Form des Verstandes und der Vernunft selbst und den allgemeinen Regeln des Denkens überhaupt ohne Unterschied der Objecte. Die formale Philosophie heißt Logik, die materiale aber, welche es mit bestimmten Gegenständen und den Gesetzen zu thun hat, denen sie unterworfen sind, ist wiederum zwiefach. Denn diese Gesetze sind entweder Gesetze der Natur, oder der Freiheit. Die Wissenschaft von der ersten heißt Physik, die der andern ist Ethik; jene wird auch Naturlehre, diese Sittenlehre genannt.
Die Logik kann keinen empirischen Theil haben, d. i. einen solchen, da die allgemeinen und nothwendigen Gesetze des Denkens auf Gründen beruhten, die von der Erfahrung hergenommen wären; denn sonst wäre sie nicht Logik, d. i. ein Kanon für den Verstand oder die Vernunft, der bei allem Denken gilt und demonstrirt werden muß. Dagegen können sowohl die natürliche, als sittliche Weltweisheit jede ihren empirischen Theil haben, weil jene der Natur als einem Gegenstande der Erfahrung, diese aber dem Willen des Menschen, so fern er durch die Natur afficirt wird, ihre Gesetze bestimmen muß, die erstern zwar als Gesetze, nach denen alles
388 geschieht, die zweiten als solche, nach denen alles geschehen soll, aber doch auch mit Erwägung der Bedingungen, unter denen es öfters nicht geschieht.
Man kann alle Philosophie, so fern sie sich auf Gründe der Erfahrung fußt, empirische, die aber, so lediglich aus Principien a priori ihre Lehren vorträgt, reine Philosophie nennen. Die letztere, wenn sie bloß formal ist, heißt Logik; ist sie aber auf bestimmte Gegenstände des Verstandes eingeschränkt, so heißt sie Metaphysik.
Auf solche Weise entspringt die Idee einer zwiefachen Metaphysik, einer Metaphysik der Natur und einer Metaphysik der Sitten. Die Physik wird also ihren empirischen, aber auch einen rationalen Theil haben; die Ethik gleichfalls, wiewohl hier der empirische Theil besonders praktische Anthropologie, der rationale aber eigentlich Moral heißen könnte.
Alle Gewerbe, Handwerke und Künste haben durch die Vertheilung der Arbeiten gewonnen, da nämlich nicht einer alles macht, sondern jeder sich auf gewisse Arbeit, die sich ihrer Behandlungsweise nach von andern merklich unterscheidet, einschränkt, um sie in der größten Vollkommenheit und mit mehrerer Leichtigkeit leisten zu können. Wo die Arbeiten so nicht unterschieden und vertheilt werden, wo jeder ein Tausendkünstler ist, da liegen die Gewerbe noch in der größten Barbarei. Aber ob dieses zwar für sich ein der Erwägung nicht unwürdiges Object wäre, zu fragen: ob die reine Philosophie in allen ihren Theilen nicht ihren besondern Mann erheische, und es um das Ganze des gelehrten Gewerbes nicht besser stehen würde, wenn die, so das Empirische mit dem Rationalen dem Geschmacke des Publicums gemäß nach allerlei ihnen selbst unbekannten Verhältnissen gemischt zu verkaufen gewohnt sind, die sich Selbstdenker, andere aber, die den bloß rationalen Theil zubereiten, Grübler nennen, gewarnt würden, nicht zwei Geschäfte zugleich zu treiben, die in der Art, sie zu behandeln, gar sehr verschieden sind, zu deren jedem vielleicht ein besonderes Talent erfordert wird, und deren Verbindung in einer Person nur Stümper hervorbringt: so frage ich hier doch nur, ob nicht die Natur der Wissenschaft es erfordere, den empirischen von dem rationalen Theile jederzeit sorgfältig abzusondern und vor der eigentlichen (empirischen) Physik eine Metaphysik der Natur, vor der praktischen Anthropologie aber eine Metaphysik der Sitten voranzuschicken, die von allem Empirischen sorgfältig gesäubert sein müßten, um zu wissen, wie viel reine Vernunft in beiden Fällen leisten
389 könne, und aus welchen Quellen sie selbst diese ihre Belehrung a priori schöpfe, es mag übrigens das letztere Geschäfte von allen Sittenlehrern (deren Name Legion heißt) oder nur von einigen, die Beruf dazu fühlen, getrieben werden.
Da meine Absicht hier eigentlich auf die sittliche Weltweisheit gerichtet ist, so schränke ich die vorgelegte Frage nur darauf ein: ob man nicht meine, daß es von der äußersten Nothwendigkeit sei, einmal eine reine Moralphilosophie zu bearbeiten, die von allem, was nur empirisch sein mag und zur Anthropologie gehört, völlig gesäubert wäre; denn daß es eine solche geben müsse, leuchtet von selbst aus der gemeinen Idee der Pflicht und der sittlichen Gesetze ein. Jedermann muß eingestehen, daß ein Gesetz, wenn es moralisch, d. i. als Grund einer Verbindlichkeit, gelten soll, absolute Nothwendigkeit bei sich führen müsse; daß das Gebot: du sollt nicht lügen, nicht etwa bloß für Menschen gelte, andere vernünftige Wesen sich aber daran nicht zu kehren hätten, und so alle übrige eigentliche Sittengesetze; daß mithin der Grund der Verbindlichkeit hier nicht in der Natur des Menschen, oder den Umständen in der Welt, darin er gesetzt ist, gesucht werden müsse, sondern a priori lediglich in Begriffen der reinen Vernunft, und daß jede andere Vorschrift, die sich auf Principien der bloßen Erfahrung gründet, und sogar eine in gewissem Betracht allgemeine Vorschrift, so fern sie sich dem mindesten Theile, vielleicht nur einem Bewegungsgrunde nach auf empirische Gründe stützt, zwar eine praktische Regel, niemals aber ein moralisches Gesetz heißen kann.
Also unterscheiden sich die moralischen Gesetze sammt ihren Principien unter allem praktischen Erkenntnisse von allem übrigen, darin irgend etwas Empirisches ist, nicht allein wesentlich, sondern alle Moralphilosophie beruht gänzlich auf ihrem reinen Theil, und auf den Menschen angewandt, entlehnt sie nicht das mindeste von der Kenntniß desselben (Anthropologie), sondern giebt ihm, als vernünftigem Wesen, Gesetze a priori, die freilich noch durch Erfahrung geschärfte Urtheilskraft erfordern, um theils zu unterscheiden, in welchen Fällen sie ihre Anwendung haben, theils ihnen Eingang in den Willen des Menschen und Nachdruck zur Ausübung zu verschaffen, da dieser, als selbst mit so viel Neigungen afficirt, der Idee einer praktischen reinen Vernunft zwar fähig, aber nicht so leicht vermögend ist, sie in seinem Lebenswandel in concreto wirksam zu machen.
Eine Metaphysik der Sitten ist also unentbehrlich nothwendig, nicht bloß aus einem Bewegungsgrunde der Speculation, um die Quelle der a
390 priori in unserer Vernunft liegenden praktischen Grundsätze zu erforschen, sondern weil die Sitten selber allerlei Verderbniß unterworfen bleiben, so lange jener Leitfaden und oberste Norm ihrer richtigen Beurtheilung fehlt. Denn bei dem, was moralisch gut sein soll, ist es nicht genug, daß es dem sittlichen Gesetze gemäß sei, sondern es muß auch um desselben willen geschehen; widrigenfalls ist jene Gemäßheit nur sehr zufällig und mißlich, weil der unsittliche Grund zwar dann und wann gesetzmäßige, mehrmals aber gesetzwidrige Handlungen hervorbringen wird. Nun ist aber das sittliche Gesetz in seiner Reinigkeit und Ächtheit (woran eben im Praktischen am meisten gelegen ist) nirgend anders, als in einer reinen Philosophie zu suchen, also muß diese (Metaphysik) vorangehen, und ohne sie kann es überall keine Moralphilosophie geben; selbst verdient diejenige, welche jene reine Principien unter die empirischen mischt, den Namen einer Philosophie nicht (denn dadurch unterscheidet diese sich eben von der gemeinen Vernunfterkenntniß, daß sie, was diese nur vermengt begreift, in abgesonderter Wissenschaft vorträgt), viel weniger einer Moralphilosophie, weil sie eben durch diese Vermengung sogar der Reinigkeit der Sitten selbst Abbruch thut und ihrem eigenen Zwecke zuwider verfährt.
Man denke doch ja nicht, daß man das, was hier gefordert wird, schon an der Propädeutik des berühmten Wolff vor seiner Moralphilosophie, nämlich der von ihm so genannten allgemeinen praktischen Weltweisheit, habe, und hier also nicht eben ein ganz neues Feld einzuschlagen sei. Eben darum, weil sie eine allgemeine praktische Weltweisheit sein sollte, hat sie keinen Willen von irgend einer besondern Art, etwa einen solchen, der ohne alle empirische Bewegungsgründe, völlig aus Principien a priori, bestimmt werde, und den man einen reinen Willen nennen könnte, sondern das Wollen überhaupt in Betrachtung gezogen mit allen Handlungen und Bedingungen, die ihm in dieser allgemeinen Bedeutung zukommen, und dadurch unterscheidet sie sich von einer Metaphysik der Sitten, eben so wie die allgemeine Logik von der Transscendentalphilosophie, von denen die erstere die Handlungen und Regeln des Denkens überhaupt, diese aber bloß die besondern Handlungen und Regeln des reinen Denkens, d. i. desjenigen, wodurch Gegenstände völlig a priori erkannt werden, vorträgt. Denn die Metaphysik der Sitten soll die Idee und die Principien eines möglichen reinen Willens untersuchen und nicht die Handlungen und Bedingungen des menschlichen Wollens überhaupt, welche größtentheils aus der Psychologie geschöpft werden. Daß in der allgemeinen
391 praktischen Weltweisheit (wiewohl wider alle Befugniß) auch von moralischen Gesetzen und Pflicht geredet wird, macht keinen Einwurf wider meine Behauptung aus. Denn die Verfasser jener Wissenschaft bleiben ihrer Idee von derselben auch hierin treu; sie unterscheiden nicht die Bewegungsgründe, die als solche völlig a priori bloß durch Vernunft vorgestellt werden und eigentlich moralisch sind, von den empirischen, die der Verstand bloß durch Vergleichung der Erfahrungen zu allgemeinen Begriffen erhebt, sondern betrachten sie, ohne auf den Unterschied ihrer Quellen zu achten, nur nach der größeren oder kleineren Summe derselben (indem sie alle als gleichartig angesehen werden) und machen sich dadurch ihren Begriff von Verbindlichkeit, der freilich nichts weniger als moralisch, aber doch so beschaffen ist, als es in einer Philosophie, die über den Ursprung aller möglichen praktischen Begriffe, ob sie auch a priori oder bloß a posteriori stattfinden, gar nicht urtheilt, nur verlangt werden kann.
Im Vorsatze nun, eine Metaphysik der Sitten dereinst zu liefern, lasse ich diese Grundlegung vorangehen. Zwar giebt es eigentlich keine andere Grundlage derselben, als die Kritik einer reinen praktischen Vernunft, so wie zur Metaphysik die schon gelieferte Kritik der reinen speculativen Vernunft. Allein theils ist jene nicht von so äußerster Nothwendigkeit als diese, weil die menschliche Vernunft im Moralischen selbst beim gemeinsten Verstande leicht zu großer Richtigkeit und Ausführlichkeit gebracht werden kann, da sie hingegen im theoretischen, aber reinen Gebrauch ganz und gar dialektisch ist: theils erfordere ich zur Kritik einer reinen praktischen Vernunft, daß, wenn sie vollendet sein soll, ihre Einheit mit der speculativen in einem gemeinschaftlichen Princip zugleich müsse dargestellt werden können, weil es doch am Ende nur eine und dieselbe Vernunft sein kann, die bloß in der Anwendung unterschieden sein muß. Zu einer solchen Vollständigkeit konnte ich es aber hier noch nicht bringen, ohne Betrachtungen von ganz anderer Art herbeizuziehen und den Leser zu verwirren. Um deswillen habe ich mich statt der Benennung einer Kritik der reinen praktischen Vernunft der von einer Grundlegung zur Metaphysik der Sitten bedient.
Weil aber drittens auch eine Metaphysik der Sitten ungeachtet des abschreckenden Titels dennoch eines großen Grades der Popularität und Angemessenheit zum gemeinen Verstande fähig ist, so finde ich für nützlich, diese Vorarbeitung der Grundlage davon abzusondern, um das Subtile,
392 was darin unvermeidlich ist, künftig nicht faßlichern Lehren beifügen zu dürfen.
Gegenwärtige Grundlegung ist aber nichts mehr, als die Aufsuchung und Festsetzung des obersten Princips der Moralität, welche allein ein in seiner Absicht ganzes und von aller anderen sittlichen Untersuchung abzusonderndes Geschäfte ausmacht. Zwar würden meine Behauptungen über diese wichtige und bisher bei weitem noch nicht zur Gnugthuung erörterte Hauptfrage durch Anwendung desselben Princips auf das ganze System viel Licht und durch die Zulänglichkeit, die es allenthalben blicken läßt, große Bestätigung erhalten: allein ich mußte mich dieses Vortheils begeben, der auch im Grunde mehr eigenliebig, als gemeinnützig sein würde, weil die Leichtigkeit im Gebrauche und die scheinbare Zulänglichkeit eines Princips keinen ganz sicheren Beweis von der Richtigkeit desselben abgiebt, vielmehr eine gewisse Parteilichkeit erweckt, es nicht für sich selbst, ohne alle Rücksicht auf die Folge, nach aller Strenge zu untersuchen und zu wägen.
Ich habe meine Methode in dieser Schrift so genommen, wie ich glaube, daß sie die schicklichste sei, wenn man vom gemeinen Erkenntnisse zur Bestimmung des obersten Princips desselben analytisch und wiederum zurück von der Prüfung dieses Princips und den Quellen desselben zur gemeinen Erkenntniß, darin sein Gebrauch angetroffen wird, synthetisch den Weg nehmen will. Die Eintheilung ist daher so ausgefallen:
1 Erster Abschnitt: Übergang von der gemeinen sittlichen Vernunfterkenntniß zur philosophischen.
2 Zweiter Abschnitt: Übergang von der populären Moralphilosophie zur Metaphysik der Sitten.
3 Dritter Abschnitt: Letzter Schritt von der Metaphysik der Sitten zur Kritik der reinen praktischen Vernunft.
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.
385 Groundwork of the Metaphysics of Morals
by Immanuel Kant.
387 Preface.
Ancient Greek philosophy divided into three sciences: physics, ethics, and logic. This division perfectly suits the nature of the subject. Nothing needs improving in it, except perhaps to add the principle on which it rests, both to assure ourselves of its completeness and to determine the necessary subdivisions correctly.
All rational cognition is either material, considering some object, or formal, concerned only with the form of understanding and reason themselves and with the universal rules of thinking as such, without distinction of objects. Formal philosophy is called logic. Material philosophy, which deals with determinate objects and the laws to which they are subject, is in turn twofold. For these laws are either laws of nature or laws of freedom. The science of the former is called physics; that of the latter, ethics. The first is also called the doctrine of nature, the second the doctrine of morals.
Logic can have no empirical part—that is, no part in which the universal and necessary laws of thinking rest on grounds drawn from experience. Otherwise it would not be logic: a canon for understanding or reason that holds for all thinking and must be demonstrated. Natural and moral philosophy, by contrast, can each have an empirical part. The former must determine the laws of nature as an object of experience; the latter, the laws of the human will insofar as nature affects it. The first are laws according to which everything
388 happens; the second, laws according to which everything ought to happen, though with consideration also of the conditions under which it often does not happen.
All philosophy, insofar as it rests on grounds of experience, may be called empirical; philosophy that presents its teachings solely from a priori principles may be called pure philosophy. When the latter is merely formal, it is called logic; when it is restricted to determinate objects of understanding, it is called metaphysics.
In this way the idea of a twofold metaphysics arises: a metaphysics of nature and a metaphysics of morals. Physics will therefore have its empirical part, but also a rational part; ethics will have the same, although here the empirical part might specifically be called practical anthropology, and the rational part morality proper.
All trades, crafts, and arts have benefited from the division of labor. Instead of one person doing everything, each confines himself to a particular kind of work, markedly different from others in how it must be handled, so that he can accomplish it with the greatest perfection and greater ease. Where work is not distinguished and divided in this way, where everyone is a jack-of-all-trades, the trades remain in the deepest barbarism. It would indeed be worth considering whether pure philosophy in all its parts does not require its own specialist. Would the whole enterprise of learning not fare better if those accustomed to selling a mixture of the empirical and the rational, blended to the public's taste in all sorts of proportions unknown even to themselves—those who call themselves independent thinkers, but call those who prepare the purely rational part brooders—were warned not to practice two occupations at once? These occupations differ greatly in the way they must be pursued; each may require a special talent, and combining them in one person produces only bunglers. But here I ask only whether the nature of science does not require us always to separate the empirical from the rational part carefully, placing a metaphysics of nature before physics proper, or empirical physics, and a metaphysics of morals before practical anthropology. Both forms of metaphysics would have to be carefully cleared of everything empirical, so that we might know how much pure reason can accomplish in either case
389 and from what sources it draws this a priori instruction of its own. It makes no difference whether the latter task is undertaken by all moral teachers, whose name is Legion, or only by some who feel called to it.
Since my purpose here is directed specifically toward moral philosophy, I restrict the question posed to this: must we not consider it supremely necessary to develop, for once, a pure moral philosophy, entirely cleared of everything that might be empirical and belong to anthropology? That such a philosophy must exist is evident from the ordinary idea of duty and moral laws. Everyone must acknowledge that a law, if it is to hold morally—that is, as the ground of an obligation—must carry absolute necessity with it. The command “You shall not lie” cannot hold only for human beings, leaving other rational beings free to disregard it; the same applies to all other moral laws in the proper sense. The ground of obligation must therefore be sought not in human nature or in the circumstances of the world in which a human being is placed, but a priori, solely in concepts of pure reason. Any other prescription founded on principles of mere experience—even one that is universal in a certain respect—can be called a practical rule but never a moral law if even the smallest part of it, perhaps only one motive, rests on empirical grounds.
Thus moral laws, together with their principles, differ not only essentially, within practical cognition as a whole, from everything else that contains anything empirical, but all moral philosophy rests entirely on its pure part; and, applied to human beings, it borrows not the slightest thing from knowledge of them, or anthropology, but gives them laws a priori as rational beings. These laws do, of course, still require judgment sharpened by experience, partly to distinguish the cases in which they apply, partly to gain them admission to the human will and give them force in practice. For the human being, affected by so many inclinations, is indeed capable of the idea of a practical pure reason, but cannot so readily make it effective in concreto in the conduct of life.
A metaphysics of morals is therefore indispensably necessary, not merely from a speculative motive, to investigate the source of the practical principles that lie a
390 priori in our reason, but because morals themselves remain exposed to every kind of corruption so long as we lack that guiding thread and supreme norm for judging them correctly. For something to be morally good, it is not enough that it conform to the moral law; it must also be done for the sake of that law. Otherwise the conformity is only highly contingent and precarious, because a nonmoral ground will indeed sometimes produce actions in accordance with the law, but will repeatedly produce actions contrary to it. Yet the moral law in its purity and genuineness—which matter most of all in practical affairs—is to be sought nowhere but in a pure philosophy. This philosophy, or metaphysics, must therefore come first; without it there can be no moral philosophy at all. A philosophy that mixes these pure principles with empirical ones does not even deserve the name of philosophy. For philosophy is distinguished from ordinary rational cognition precisely by presenting in a separate science what the latter grasps only in a mixture. Still less does it deserve the name of moral philosophy, since by this very mixture it actually impairs the purity of morals themselves and defeats its own purpose.
We must certainly not suppose that what is required here is already supplied by the introductory discipline that the celebrated Wolff placed before his moral philosophy, namely what he called general practical philosophy, and that there is therefore no wholly new field to enter. Precisely because it was intended as a general practical philosophy, it considered no will of a particular kind—for example, one determined without any empirical motives, entirely from a priori principles, which might be called a pure will. It considered willing in general, with all the actions and conditions belonging to it in this general sense. It thus differs from a metaphysics of morals just as general logic differs from transcendental philosophy. The former presents the actions and rules of thinking in general; the latter, only the particular actions and rules of pure thinking, that is, of thinking through which objects are cognized entirely a priori. For a metaphysics of morals must investigate the idea and principles of a possible pure will, not the actions and conditions of human willing in general, which are drawn for the most part from psychology. That general
391 practical philosophy also speaks of moral laws and duty—though without any justification—constitutes no objection to my claim. For here too the authors of that science remain faithful to their idea of it. They do not distinguish motives presented as such entirely a priori by reason alone, which are properly moral, from empirical motives that understanding raises to universal concepts merely by comparing experiences. Instead, without attending to the difference in their sources, they consider only their greater or smaller sum, treating them all as of the same kind. In this way they form their concept of obligation: a concept that is certainly anything but moral, yet is all that can be demanded in a philosophy that makes no judgment at all about the origin of all possible practical concepts—whether they occur a priori or merely a posteriori.
Intending, then, to provide a metaphysics of morals someday, I am putting this groundwork first. Strictly speaking, there is no foundation for such a metaphysics other than the critique of a pure practical reason, just as the critique of pure speculative reason already provided is the foundation for metaphysics. Yet, for one thing, the former is not as supremely necessary as the latter. In moral matters, human reason can readily be brought to great correctness and thoroughness even in the most ordinary understanding, whereas in its theoretical but pure use it is altogether dialectical. For another, I require of a critique of pure practical reason that, if it is to be complete, its unity with speculative reason must also be capable of presentation in a common principle. For ultimately there can be only one and the same reason, which must be distinguished merely in its application. But I could not yet achieve such completeness here without introducing considerations of an entirely different kind and confusing the reader. I have therefore used the title Groundwork of the Metaphysics of Morals rather than Critique of Pure Practical Reason.
Third, even a metaphysics of morals, despite its forbidding title, admits a high degree of accessibility and suitability for ordinary understanding. I therefore find it useful to separate this preliminary treatment of its foundation from it, so that I shall not later have to attach the subtleties
392 unavoidable here to teachings that are easier to grasp.
The present groundwork, however, is nothing more than the search for and establishment of the supreme principle of morality. This alone is an undertaking complete in its purpose and to be separated from every other moral investigation. Applying the same principle to the whole system would indeed cast much light on my claims about this important central question, which has so far been discussed in a far from satisfactory way. The principle's adequacy, manifest everywhere, would greatly confirm them. But I had to forgo this advantage, which would at bottom serve self-love more than the common good. For ease of use and the apparent adequacy of a principle provide no wholly secure proof of its correctness. Rather, they awaken a certain bias against examining and weighing the principle with full rigor on its own, without any regard to what follows from it.
I have adopted in this work the method I believe most suitable if we wish to proceed analytically from ordinary cognition to the determination of its supreme principle, and then synthetically back from the examination of this principle and its sources to the ordinary cognition in which we find it used. The division is therefore as follows:
1 First section: Transition from ordinary moral rational cognition to philosophical cognition.
2 Second section: Transition from popular moral philosophy to the metaphysics of morals.
3 Third section: Final step from the metaphysics of morals to the critique of pure practical 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.
385 Groundwork for the Metaphysics of Morals, by Immanuel Kant.
387 Preface.
Ancient Greek philosophy was divided into three sciences: physics, ethics and logic. This division fits the nature of the subject perfectly. It needs no improvement, except perhaps to add the principle on which it rests. In this way we can both make sure that the division is complete and determine the necessary subdivisions correctly.
All cognition by reason is either material or formal. Material cognition considers some object. Formal cognition deals only with the form of the understanding and of reason itself, and with the general rules of thinking as such, without distinguishing between objects. Formal philosophy is called logic. Material philosophy deals with determinate objects and with the laws they are subject to, and it is in turn twofold. For these laws are either laws of nature or laws of freedom. The science of the first is called physics, and the science of the second is ethics. The first is also called the doctrine of nature, and the second the doctrine of morals.
Logic cannot have an empirical part. By that I mean a part in which the universal and necessary laws of thinking would rest on grounds taken from experience. If it had such a part, it would not be logic, which is a canon for the understanding or reason that holds for all thinking and has to be demonstrated. Natural philosophy and moral philosophy, by contrast, can each have an empirical part. The reason is that natural philosophy must lay down its laws for nature as an object of experience, and moral philosophy must lay down its laws for the human will, insofar as nature affects it. The laws of the first are laws by which everything
388 happens. The laws of the second are laws by which everything ought to happen. Yet they also take into account the conditions under which it often does not happen.
All philosophy, insofar as it rests on grounds of experience, we can call empirical philosophy. Philosophy that presents its teachings solely from principles a priori we can call pure philosophy. When pure philosophy is only formal, it is called logic. When it is limited to determinate objects of the understanding, it is called metaphysics.
In this way the idea of a twofold metaphysics arises: a metaphysics of nature and a metaphysics of morals. Physics will therefore have its empirical part, but also a rational part. Ethics will too. Here, though, the empirical part could be called in particular practical anthropology, and the rational part properly morals.
All trades, crafts and arts have gained from the division of labor. One person does not make everything. Instead each person sticks to a certain kind of work that differs clearly from the others in how it is handled, so as to do it with the greatest perfection and with more ease. Where work is not distinguished and divided in this way, where everyone is a jack-of-all-trades, the trades are still in the deepest barbarism. It would be worth considering, in itself, whether pure philosophy in all its parts does not call for its own particular person, and whether the whole scholarly trade would not be better off if a warning were given to certain people. These people are used to selling the empirical mixed with the rational, to suit the public's taste, in all sorts of proportions unknown even to themselves. They call themselves independent thinkers, and they call others, who prepare only the rational part, brooders. The warning would be not to carry on two businesses at once. The two are very different in how they are handled. Each may perhaps need its own special talent. Joining them in one person produces only bunglers. But here I ask only this: does the nature of the science not require that the empirical part always be carefully separated from the rational part? Before physics proper (the empirical kind), a metaphysics of nature should be put first. Before practical anthropology, a metaphysics of morals should be put first. Both would have to be carefully cleaned of everything empirical, so that we can know how much pure reason in both cases
389 can achieve, and from what sources it draws this teaching of its own a priori. It does not matter whether the latter task is taken up by all teachers of morals (whose name is Legion) or only by some who feel called to it.
My aim here is really moral philosophy, so I limit the question just put to this one: does one not think that it is extremely necessary to work out, at last, a pure moral philosophy, one completely cleaned of everything that may be merely empirical and belongs to anthropology? That there must be such a philosophy is obvious by itself from the ordinary idea of duty and of moral laws. Everyone must admit the following. A law, if it is to count as moral, that is, as the ground of an obligation, must carry absolute necessity with it. The command "You must not lie" does not hold merely for human beings, as if other rational beings need not heed it. The same goes for all the other laws that are properly moral. It follows that the ground of obligation here must not be sought in the nature of the human being, or in the circumstances of the world in which the human being is placed. Instead it must be sought a priori, solely in concepts of pure reason. And any other instruction that is founded on principles of mere experience can be called a practical rule, but never a moral law. This holds even for an instruction that is general in a certain respect, insofar as it rests on empirical grounds in even the smallest part, perhaps only in respect of one motive.
Moral laws, together with their principles, therefore differ not only in essence from everything else in practical cognition that has anything empirical in it. All moral philosophy also rests entirely on its pure part. When it is applied to human beings, it borrows nothing at all from knowledge of them (anthropology). Instead it gives them, as rational beings, laws a priori. These laws do, to be sure, still require a power of judgment sharpened by experience. It is needed partly to tell in which cases the laws apply, and partly to win them entry into the human will and force for carrying them out. For human beings are themselves affected by so many inclinations. They are capable of the idea of a practical pure reason, but they are not so easily able to make it effective in their way of life in concreto.
A metaphysics of morals is therefore indispensable and necessary. It is not needed merely for a speculative motive, to investigate the source of the a
390 priori practical principles that lie in our reason. It is needed because morals themselves remain subject to all kinds of corruption as long as that guide and highest norm for judging them correctly is missing. For something that is to be morally good, it is not enough that it be in accordance with the moral law. It must also be done for the law's sake. Otherwise the accordance is only very accidental and uncertain, because the immoral ground will now and then produce actions that fit the law, but more than once actions that go against it. Now the moral law, in its purity and genuineness (which is just what matters most in practice), is to be sought nowhere else than in a pure philosophy. So this philosophy (metaphysics) must come first. Without it there can be no moral philosophy at all. Indeed, whatever mixes those pure principles in with the empirical ones does not deserve the name of philosophy. (For this is just how philosophy differs from ordinary cognition by reason: it presents in a separate science what ordinary cognition grasps only in a mixed-up way.) Much less does it deserve the name of moral philosophy, because by this very mixing it damages even the purity of morals themselves, and it works against its own purpose.
Let no one think that what is asked for here is already found in the preparatory study that the famous Wolff put before his moral philosophy, the one he called general practical philosophy, and that a wholly new field is therefore not really being entered here. Precisely because it was meant to be a general practical philosophy, it takes up no will of any particular kind. It does not take up, for example, a will that is determined entirely from principles a priori, without any empirical motives, which one could call a pure will. Instead it looks at willing in general, with all the actions and conditions that belong to willing in this general sense. This is how it differs from a metaphysics of morals, just as general logic differs from transcendental philosophy. General logic presents the actions and rules of thinking in general. Transcendental philosophy presents only the particular actions and rules of pure thinking, that is, of the thinking by which objects are known entirely a priori. For the metaphysics of morals is meant to investigate the idea and the principles of a possible pure will. It is not meant to investigate the actions and conditions of human willing in general, most of which are drawn from psychology. The fact that in the general
391 practical philosophy moral laws and duty are also spoken of (though with no right to do so) is no objection to my claim. For the authors of that science stay true to their idea of it here too. They do not distinguish the motives that, as such, are represented entirely a priori by reason alone and that are properly moral, from the empirical motives that the understanding raises to general concepts merely by comparing experiences. Instead they consider the motives without paying attention to the difference in their sources. They look only at how large or small the total of them is, since all are regarded as being of the same kind. In this way they form their concept of obligation. This concept is certainly anything but moral. Still, it is as good as can be demanded in a philosophy that passes no judgment at all on the origin of all possible practical concepts, whether they occur a priori or merely a posteriori.
I intend to supply a metaphysics of morals some day, and I let this groundwork come first. Strictly speaking, there is no other foundation for such a metaphysics than the critique of a pure practical reason, just as the critique of pure speculative reason, which has already been supplied, is the foundation for metaphysics. But for one thing, the former is not as extremely necessary as the latter. In morals, human reason can easily be brought to great correctness and completeness, even with the most ordinary understanding. In theoretical but pure use, by contrast, it is dialectical through and through. For another thing, I require of a critique of pure practical reason that, if it is to be complete, its unity with speculative reason must be able to be shown at the same time in a common principle. For in the end there can be only one and the same reason, which must differ merely in its application. I could not yet reach such completeness here without bringing in considerations of a quite different kind and confusing the reader. For that reason I have used the title Groundwork for the Metaphysics of Morals instead of the title Critique of Pure Practical Reason.
Third, even a metaphysics of morals is nevertheless capable, despite its forbidding title, of a high degree of popularity and of suitability for the ordinary understanding. So I find it useful to separate this preliminary work on the foundation from it, so that the subtle part
392 that is unavoidable in it need not be added later to teachings that are easier to grasp.
The present groundwork is nothing more than the search for and establishment of the supreme principle of morality. This alone makes up a task that is complete in its aim and that must be kept separate from all other moral inquiry. True, applying the same principle to the whole system would shed much light on my claims about this important main question, which so far has by no means been discussed satisfactorily. The adequacy that the principle shows everywhere would also strongly confirm those claims. But I had to give up this advantage. At bottom it would also serve self-love more than the common good. The ease of using a principle and its apparent adequacy do not give fully certain proof that the principle is correct. They rather arouse a certain partiality toward not examining and weighing it strictly for itself, without any regard to what follows from it.
In this work I have chosen my method as the one I believe most suitable, if one wants to take the road analytically from ordinary cognition to the determination of its supreme principle, and then back again synthetically from the examination of this principle and its sources to ordinary cognition, where the principle is found in use. The division has therefore come out like this:
1 First Section: Transition from ordinary moral cognition by reason to philosophical cognition by reason.
2 Second Section: Transition from popular moral philosophy to the metaphysics of morals.
3 Third Section: Final step from the metaphysics of morals to the critique of pure practical reason.
About this section
Preface 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 1 of 4 in the work, which is kept in the European tradition.
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