Hippocrates as Galen's teacher.

Starting from the frescoes of the cathedral of Anagni which present an obvious relationship between Hippocrates as Galen's teacher and the medieval image of man's place in the universe dominated by the number four, this paper returns to the origins of this quaternary theory in Hippocratic medicine with the four humors (Nature of Man), then follows its evolution in Galen and finally into late Greek and Byzantine medicine where the quaternary division will have an unprecedented extension, with the four temperaments. In particular, a new piece of evidence from this late period attributed to Hippocrates (the small treatise of Greek Medicine The Pulse and the Human Temperament) appears as the veritable source of the Latin Letter attributed to Vindicianus. Therefore, contrary to what was believed until now, the doctrine of the four temperaments was not elaborated first in a Latin form. Throughout its history, the quaternary theory will remain connected to Hippocrates, but the image and teaching of the Father of Medicine will change as the theory evolves. A second rediscovered treatise of the late period (The Formation of Man) starts with this phrase: 'Words of Hippocrates to Galen his own pupil'. This seems a felicitous commentary to the medical scene in the cathedral of Anagni.