Dissections were impossible; their physiology was of the crudest character, strongly dominated by the philosophies.

Empedocles regarded the four elements, fire, air, earth and water, as "the roots of all things," and this became the corner stone in the humoral pathology of Hippocrates.

As in the Macrocosm--the world at large there were four elements, fire, air, earth, and water, so in the Microcosm--the world of man's body--there were four humors (elements), viz.,blood, phlegm, yellow bile (or choler) and black bile (or melancholy), and they corresponded to the four qualities of matter, heat, cold, dryness and moisture.

For more than two thousand years these views prevailed.

In his "Regiment of Life" (1546) Thomas Phaer says:".