SOURCE: “Democritus and the Origins of Moral Psychology,” in American Journal of Philology, Vol. 106, No. 1, 1985, pp. 1-31.

In the following essay, Kahn explores Democritus's texts as a source for moral psychology and ethics in the time of Socrates.

The fragments of Democritus constitute the most important body of material for the history of philosophical ethics and psychology before the dialogues of Plato. This fact has not received the attention it deserves, largely because interest in Democritus has focused on his physical doctrines. The physical theory is known to us from Aristotle and the doxography, but the fragments themselves speak primarily about matters of conduct, moral psychology, and the conditions of happiness. Now of pre-Platonic philosophers whose written work has reached us, only Heraclitus and Democritus deal with such themes. We have every reason to believe that Socrates did so too, but there is no pre-Platonic documentation for his...