470?-399 B.C.

Greek philosopher who exerted a profound influence on subsequent critical thought and intellectual development in ancient Greece. Socrates left no writings of his own; it is only through his pupils, mainly Plato, that we know of his ideas. While not directly concerned with what may be regarded as science, his philosophy shaped later developments. His emphasis on human life, as opposed to the heavens, led to new study of the physical world. His philosophical method—starting with a likely hypothesis, then considering the consequences—is still influential. Found guilty of corrupting the Athenian youth with his ideas, he committed suicide.