Book 5, Chapter 4

10 Pythagoras did not merely invent the name: he also enlarged the subject itself. After this conversation at Phlius he came to Italy, and adorned the Greece that was called Great with the finest institutions and arts, both in private and in public life. Perhaps another occasion will come to speak of his teaching. From the earliest philosophy down to Socrates, who had studied under Archelaus, the pupil of Anaxagoras, philosophers investigated numbers and movements, the sources from which all things arise and the ends to which they return. They eagerly examined the sizes, distances, and courses of the stars, and everything in the heavens. Socrates was the first to call philosophy down from heaven, establish it in cities, introduce it even into homes, and compel it to inquire into life and conduct, good and evil.

11 The many forms of his reasoning, the range of his subjects, and the greatness of his intellect, preserved and made immortal in Plato’s writings, gave rise to several schools of philosophers who disagreed with one another. Of these we have chiefly followed what we believed to be Socrates’ own practice: to conceal our own opinion, free others from error, and in every discussion seek what most closely resembles the truth. Carneades pursued this method with exceptional acuteness and fullness, and we too have often discussed subjects in this manner, most recently at Tusculum. I have sent you the conversations of the first four days, fully written out in the preceding books. On the fifth day we sat down in the same place, and the following proposition was put forward for discussion:

10 Besides coming up with the name, Pythagoras did much to expand the subject itself. He went to Italy after the conversation at Phlius. There, in the Greek region known as Greater Greece, he introduced excellent practices and skills for public as well as private life. We may have another occasion to speak about his teaching. Early philosophy, all the way down to Socrates, dealt with numbers and motion, the origins of everything and what everything passes back into. Socrates himself had been taught by Archelaus, a pupil of Anaxagoras. Those philosophers took pains to work out how large the stars were, how far apart, and how they moved, along with everything else in the sky. With Socrates, for the first time, philosophy left the heavens and came to live in our cities—even inside our homes. He required it to investigate how people live and behave, and which things are good or bad.

11 Socrates had many ways of arguing, a wide range of subjects, and a great intellect. Plato preserved all this in his writings and gave it lasting honor. The result was several different schools of philosophers who disagreed with one another. We have chiefly followed the approach we believed Socrates used: we kept our own opinions to ourselves, freed others from their mistakes, and looked in every discussion for what came closest to the truth. Carneades practiced this method with great sharpness and fullness. We’ve often argued in that way ourselves, and recently did so at Tusculum. I’ve written out the conversations of four days in the earlier books and sent them to you. On the fifth day, when we’d sat down in the same place, this was the question put forward for discussion: