Answer me, you who believe that animals are only machines. Has nature arranged for this animal to have all the machinery of feelings only in order for it not to have any at all?
Descartes constructed as noble a road of science, from the point at which he found geometry to that to which he carried it, as Newton himself did after him. ... He carried this spirit of geometry and invention into optics, which under him became a completely new art.
Every man can educate himself. It's shameful to put one's mind into the hands of those whom you wouldn't entrust with your money. Dare to think for yourself.
The supposed right of intolerance is absurd and barbaric. It is the right of the tiger; nay, it is far worse, for tigers do but tear in order to have food, while we rend each other for paragraphs.
Love has features which pierce all hearts, he wears a bandage which conceals the faults of those beloved. He has wings, he comes quickly and flies away the same.
Sensual pleasure passes and vanishes, but the friendship between us, the mutual confidence, the delight of the heart, the enchantment of the soul, these things do not perish and can never be destroyed.
He who has heard the same thing told by 12,000 eye-witnesses has only 12,000 probabilities, which are equal to one strong probability, which is far from certain.