Humor: In medicine, humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye. The humors ran through an ancient theory that held that health came from balance between the bodily liquids. These liquids were termed humors. Disease arose when there was imbalance between these humors.
The humors were:
This theory (which was variously called the humoral theory, humoralism, and humorism) was devised well before Hippocrates (c.460-c.375 BC). It was not definitively demolished until Rudolf Virchow published his formative book, Cellularpathologie, in 1858 that laid out the cellular basis of pathology. Present day pathology rests on a cellular and molecular foundation. The humors have been dispelled, except for the aqueous humor and vitreous humor of the eye.