The word “humours” when applied to this play refers to a concept that was popular during Ben Jonson’s day. Humors were temperaments or people’s personalities. The belief was that these personalities flowed through people. The word “humour” comes from a Latin word, “humor”, which means liquid. In Medieval times, there was a medical theory that held that the human body was a balance of four humors or liquids: blood, phelgm, yellow bile (choler) and black bile (melancholy). If these liquids were balanced in one’s body, then the person was healthy. If they were out of balance, however, then the person was messed up.
In drama and literature, this theory translated into four main personality types: melancholic, sanguine, choleric and phelgmatic. Some believed that all people were primarily one of these types of personalities, although they could also have elements of the other three.
A comedy of humors refers to a type of drama that focused on characters, each character representing a type of personality. Ben Jonson was one of the main writers of this genre and you can see it in Volpone. The characters in Volpone are stereotypes. They represent a character type rather than a flesh-and-blood character whose mind we can get into when we read the play. In a comedy of humors, the characters are the most important focus, so Volpone fits this criterion. All of the characters are imbalanced as well, so their “humors” are out of sync and they thus act in comical ways. There are some characters in this play that have physical abnormalities (Nano, Castrone & Androgyno) and yet they are not as out of balance as the ones who are mentally imbalanced (Volpone, Mosca, Voltore, Corvino, Corbaccio, etc.)