I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use. (Galileo Galilei)

He is one of those people who would be enormously improved by death. (H. H. Munro (Saki))

The optimist proclaims that we live in the best of all possible worlds, and the pessimist fears this is true. (James Branch Cabell)

Each problem that I solved became a rule which served afterwards to solve other problems. (Rene Descartes, Discours de la Methode)