It requires twenty years for a man to rise from the vegetable state in which he is within his mother's womb, and from the pure animal state which is the lot of his early childhood, to the state when the maturity of reason begins to appear. It has required thirty centuries to learn a little about his structure. It would need eternity to learn something about his soul. It takes an instant to kill him.
I have lived eighty years of life and know nothing for it, but to be resigned and tell myself that flies are born to be eaten by spiders and man to be devoured by sorrow.
The system of Descartes... seemed to give a plausible reason for all those phenomena; and this reason seemed more just, as it is simple and intelligible to all capacities. But in philosophy, a student ought to doubt of the things he fancies he understands too easily, as much as of those he does not understand.