Galen

"That which is, grows, while that which is not, becomes."

"Galen himself, who was not unacquainted with Mosess writings, and with christianity, fancyd the earth had a certain soul or mind imparted to it by the superior bodies."

"A god, as I have said, commanded me to tell the first use also, and he himself knows that I have shrunk from its obscurity. He knows too that not only here but also in many other places in these commentaries, if it depended on me, I would omit demonstrations requiring astronomy, geometry, music, or any other logical discipline, lest my books should be held in utter detestation by physicians. For truly on countless occasions throughout my life I have had this experience; persons for a time talk pleasantly with me because of my work among the sick, in which they think me very well trained, but when they learn later on that I am also trained in mathematics, they avoid me for the most part and are no longer at all glad to be with me. Accordingly, I am always wary of touching on such subjects, and in this case it is only in obedience to the command of a divinity, as I have said, that I have used the theorems of geometry"

"It would be better, I think, for the man who really seeks the truth not to ask what the poets say; rather, he should first learn the method of finding the scientific premises that I discussed in the second book; then he should train and exercise himself in this method; and when his training is sufficiently advanced, then, as he approaches each particular problem, he should enquire into the premise needed for proving it, which premise he should take from simple sense-perception, which from experience, whether drawn from life or from the arts, which from the truths clearly apprehended by the mind, in order to draw out from them the desired conclusion."

"The fact is that those who are enslaved to their sects are not merely devoid of all sound knowledge, but they will not even stop to learn!"

"Triste est omne animale post coitum, praeter mulierem gallumque"

"Employment is Natures physician, and is essential to human happiness."

"The laws of nature, as analyzed mathematically and descriptively by Ptolemy and Galen, bore an interesting, and perhaps not entirely accidental similarity to the law of nations and of nature, as discerned by a long succession of Roman jurists. ...The concept of an objective law applicable to human affairs, yet operating in accord with Nature and Reason and apart both from divine revelation and from human whim or passion, was peculiar to Rome and societies descended from Rome."

"Quod optimus medicus sit quoque philosophus."

"The Roman physician Galen claimed that women could not conceive in rape—could not, in fact, conceive without an orgasm based in pleasure and consent."

"He who has two cakes of bread, let him dispose of one of them for some flowers of the narcissus; for bread is the food of the body, and the narcissus is the food of the soul."

"But it is best of all to look at the human skeleton with your own eyes."