Changes

The human body doesn't contain the same amount of each humourall four humours in equal amounts. Blood, as I've mentioned, is the most abundant humour and one, while the elusive black bile, the least. The perfect proportion is such that for each part of black bile there are four parts of regular bile, four times as many parts of phlegm and four times as much blood as the phlegm. This perfect balance, however, is never found in real life. Each person's humoral complexion is more or less out of balance; there's too much of this humour or not enough of that. Mind you, there's no such thing as "bad humour"; there's only an imbalance of humours. Just as there's no such thing as a perfectly healthy individual; everyone is more or less ill. Therefore, the goal of medicine is simple: to correct the amount of humours in the patient's body in order to bring it as close to the perfect balance as possible.