"The art of medicine is to be learned only by experience and observation."

"It is not wealth or ancestry, but rather the spirit of the age, which has raised me to the highest pinnacle of fame."

"The life of man is a perpetual motion."

"Very many maintain that all we know is still infinitely less than all that still remains unknown; nor do philosophers pin their faith to others' precepts in such wise that they lose their liberty, and…"

"I am not so mad, nor have I been so caught up in the opinion of others, as to believe that I have discovered anything so great as to be worthy of the name of a new opinion."