(1) [Alkmaion said that] concerning invisible things, just as concerning mortal things, the gods have certainty whereas all that men have is conjecture. [Aetius]

(2) Alkmaion maintains that the bond of health is the "equal balance" [isonomia] of the powers—moist and dry, cold and hot, bitter and sweet etc.—while the "supremacy" of one of them is the cause of illness; for the supremacy of either one is destructive. Illness comes about sometimes from an internal cause (such as excess of heat or cold), sometimes from an external cause (such as excess or deficiency of nourishment) and sometimes in a certain part (such as blood, marrow or brain).... Health, on the other hand, is the proportionate mixture [eukrasia] of these qualities. [ibid.]