Psychology as a science has suffered from being entangled with philosophy, and even, until recent times, with theology. The distinction between mind and matter, which was not drawn sharply by the pre-Socratics, became emphatic in Plato, in whom it was connected with religion. Christianity took over this aspect of Platonism, and made it the basis of much theological dogma. Soul and body were different substances; the soul was immortal, while the body decayed at death, though at the resurrection we should acquire a new, incorruptible body. It was the soul that sinned, and that suffered eternal punishment as the result of the Divine justice, or enjoyed eternal bliss as the result of the Divine mercy. The existence of two sorts of substance, material and mental, was accepted by all the leading scholastics; orthodoxy demanded matter just as much as mind, since Christ's Body was required for the dogma of tran-substantiation. Gradually the distinction of soul and body, which was at first a recondite metaphysical subtlety, became a part of accepted common sense, until, in our day, it is only a few metaphysicians who dare to question it.