"I am not ashamed to confess that I have learned much from women."

"The world is a book, and those who do not travel read only one page."

"In natural science the principles of truth ought to be confirmed by observation."

"The first step in wisdom is to know the things themselves."

"The calyx is the marriage bed, the corolla the bed-curtains, the filaments the spermatic vessels, the anthers the testes, the pollen the semen, the pistil the vagina, the ovary the uterus, the ovules …"