. . . not only the practical politics, but the abstract philosophies of the modern world have had this queer twist [of being contrary to common sense]. Since the modern world began in the sixteenth century, nobody's system of philosophy has really corresponded to everybody's sense of reality: to what, if left to themselves, common men would call common sense. Each started with a paradox: a peculiar point of view demanding the sacrifice of what they would call a sane point of view. That is the one thing common to Hobbes and Hegel, to Kant and Bergson, to Berkeley and William James.