The body's complexion was a balance of hot, cold, wet and dry. The health of a patient was studied by looking at the humours (liquids).
Causes of disease were seen as manifesting from the humours (a blockage of the flow), or directly influenced by God, such as the poisoning of air to create epidemics and plagues, or to punish individual sinners.
Similarly humans could use healing herbs to balance the humours, but there were also miraculous interventions by God.
The principle of the humours derived from the work of Greek physicians and particularly Galen (2nd century AD). Galen was held in huge reverence throughout the Middle Ages and Renaissance.
Come the 16th century, closer scrutiny came to be made of some of his conclusions, as a result of changes in the practice of anatomy, but Galen's status as the primary medical authority was not challenged.
Renaissance scholarship, after all, looked back to the classical world to provide inspiration and models; classical authorities might be questioned and modified, but they were not jettisoned.
Medical understanding of the time was that the body's complexion was a balance of hot, cold, wet and dry. This was the basis of the body's humours (liquids) and of every living thing, including herbs and natural substances, that could be used for healing.
Diagnosis was done by checking the patient's complexion (what colour they were) and testing the humours by looking at bodily excretions: tasting and looking at the urine.
Numerous medical text books and teaching diagrams including urine charts are held at the Wellcome Library for the History and Understanding of Medicine and the British Library.
Q. What were the principles on which medicine was based - and did it work?
Benivieni, like all his contemporaries, was educated in classical medicine, particularly the work of Galen, transmitted through Arab scholarship. His work as a physician sought to restore the right balance of humours, for these determined the health of the body; this balance was regained by a regime of drugs and diet.
The barber-surgeon stood on a lower rung of the professional ladder, called in if surgical intervention were required. Hence in an autopsy, the surgeon did the menial hands-on work, whilst the physician lectured on what was to be seen.
One of the most radical departures of Renaissance medicine in the next century was the elimination of this division in the practice of anatomy.
How effective was hospital treatment? Santa Maria Nuova had a startlingly high recovery rate - up to 90%. But we need to ask who was being admitted to the hospital in the first place.
The infectious and those with chronic long term conditions were treated in other institutions. The sort of diseases and accidents treated in Santa Maria Nuova were those which responded well to rest and chicken soup.