When in many dissections, carried out as opportunity offered upon living animals, I first addressed my mind to seeing how I could discover the function and offices of the heart's movement in animals through the use of my own eyes instead of through the books and writings of others, I kept finding the matter so truly hard and beset with difficulties that I all but thought, with Fracastoro, that the heart's movement had been understood by God alone.

I avow myself the partisan of truth alone.

For the concept of a circuit of the blood does not destroy, but rather advances traditional medicine.

The heart is the household divinity which, discharging its function, nourishes, cherishes, quickens the whole body, and is indeed the foundation of life, the source of all action.

Memory cannot exist without endurance of the things perceived, and the thing perceived cannot remain where it has never been.

Moderate labor of the body conduces to the preservation of health, and cares many initial diseases.

Civilization is only a series of victories against nature.