When you do not know the nature of the malady, leave it to nature; do not strive to hasten matters. For either nature will bring about the cure or it will itself reveal clearly what the malady really is.

Leeches should be kept a day before applying them. They should be squeezed to make them eject the contents of their stomachs.

The world is divided into men who have wit and no religion and men who have religion and no wit.

Those who deny the first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped.

Mountains have been formed by one [or other] of the causes of the formation of stone, most probably from agglutinative clay which slowly dried and petrified during ages of which we have no record. It seems likely that this habitable world was in former days uninhabitable and, indeed, submerged beneath the ocean. Then, becoming exposed little by little, it petrified in the course of ages.

Medicine is the science by which we learn the various states of the human body in health and when not in health, and the means by which health is likely to be lost and, when lost, is likely to be restored back to health. In other words, it is the art whereby health is conserved and the art whereby it is restored after being lost. While some divide medicine into a theoretical and a practical [applied] science, others may assume that it is only theoretical because they see it as a pure science. But, in truth, every science has both a theoretical and a practical side.

An ignorant doctor is the aide-de-camp of death.