Sophie's World

by Jostein Gaarder

He believed that it is essential for morality to presuppose that man has an immortal soul, that God exists, and that man has a free will.’ ‘So he does the same as Descartes. First he is very critical of everything we can understand. And then he smuggles God in by the back door.’ ‘But unlike Descartes, he emphasizes most particularly that it is not reason which brought him to this point but faith. He himself called faith in the immortal soul, in God’s existence, and in man’s free will practical postulates.’ ‘Which means?’ ‘To “postulate” something is to assume something that cannot be proved. By a “practical postulate,” Kant meant something that had to be assumed for the sake of “praxis,” or practice; that is to say, for man’s morality. “It is a moral necessity to assume the existence of God,” he said.’