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.
It is better not to apply any treatment in cases of occult cancer; for if treated (by surgery), the patients die quickly; but if not treated, they hold out for a long time.
Male and female have the power to fuse into one solid, both because both are nourished in both and because soul is the same thing in all living creatures, although the body of each is different.
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.
