Contents De Complexionibus is the name given to the Latin translation of the first three books of De Tempermentis from Galen. Based on humoral medicine (discussed in another Galenic treatise also included in MS 166), this treatise covers the 'complexions', or the concept of individual arrangements of humours in people. This idea of predominating humours is described as four 'temperaments' of people (choleric, melancholic, phlegmatic,...