Pierre-Jean-Georges Cabanis [1757-1808], an advocate of a monist or neuroscientific view of mind, writing about Democritus, an ancient Greek materialist relates the following story:
Hippocrates, called by the Abderans* to heal Democritus of his supposed madness, found him dissecting animal brains, from which he was trying to unravel the mysteries of … physical sensibility and to recognize the organs and the causes that produce thought. The two wise men spoke together on the general order of the universe, and on that of THE SMALL WORLD, or of man, with which both were almost equally occupied, …. In this conversation, Democritus appears to have felt even more the close connections between … physical and … moral states. And the doctor, as he retired, judged that it was to the Abderans, and not to the supposed patient, the the hellebore* should be administered [P-J-G Cabanis, On the Relations of the Physical and moral Aspects of man, Johns Hopkins U.P., 1981, v1,p 41].
*Abderans, residents of Abdera, Democritus' home. The air of Abdera was proverbial in Athens as causing stupidity
*Hellebore, a powerful laxitive and emetic thought to cure difficult diseases such as mania, by removing black bile.