Socrates adds to the doctrine of Protagoras the doctrine of Heraclitus, that everything is always changing, i.e. that “all the things we are pleased to say ‘are’ really are in process of becoming.”

All things originate from one another, and vanish into one another according to necessity; they give to each other justice and recompense for injustice in conformity with the order of Time.

THE Greeks were not addicted to moderation, either in their theories or in their practice. Heraclitus maintained that everything changes; Parmenides retorted that nothing changes.

Democritus was a thorough-going materialist; for him, as we have seen, the soul was composed of atoms, and thought was a physical process.

Heraclitus’ philosophy. He assumes the conflict between opposites is the basis of all existence. “They do not understand,” he says, “that the all-One, conflicting in itself, is identical with itself: conflicting harmony as in the bow and in the lyre.”[19] Or still more clearly: “We go into the same river, and yet not in the same; it is we and it is