Whoever wishes to investigate medicine should proceed thus: In the first place, consider the seasons of the year and what effect each of them produces.
When doing everything according to indications, although things may not turn out agreeably to indication, we should not change to another while the original appearances remain.
All parts of the body which have a function, if used in moderation and exercised in labors in which each is accustomed, become thereby healthy, well developed and age more slowly, but if unused they become liable to disease, defective in growth and age quickly.
First of all a natural talent is required; for when Nature opposes, everything else is in vain; but when Nature leads the way to what is most excellent, instruction in the art takes place.
Those diseases which medicines do not cure, iron cures; those which iron cannot cure, fire cures; and those which fire cannot cure, are to be reckoned wholly incurable.
