A Shift in Emphasis.

The scientific philosophers, from Thales to Democritus, had done their best to understand the nature of the world with remarkable achievement. The intuition of Leucippus and Democritus—that the universe was created of atoms and void—was a remarkable one, but the Greeks lacked the scientific equipment to make it anything more than an hypothesis. In the classical period (480–323 B.C.E.), philosophy sought new areas of speculation. In Athens, Socrates was a pivotal figure, so much so that the natural philosophers, from Thales to Democritus, are lumped together under the label, "Presocratics." Yet the way for Socrates was prepared by a group of thinkers and teachers called Sophists. The Greek word sophistes, from which the word "sophist" is derived, means a "master of one's craft," and it has a secondary meaning of "one who is expert in practical wisdom." Experts in...