As against the Manichaeans he always asserts the worth and dignity of the body. Like Aristotle he makes the soul the final cause of the body. As God is the Good or Summum Bonum of the soul, so is the soul the good of the body. The origin of the soul is perhaps beyond our ken. He never definitely decided between Traducianism and Creationism. As regards spirituality, he is everywhere most explicit, but it is interesting as an indication of the futile subtleties current at the time to find him warning a friend against the controversy on the corporeality of the soul, seeing that the term "corpus" was used in so many different senses. "Corpus, non caro" is his own description of the angelic body. Medieval psychology prior to the Aristotelean revival was affected by neo-Platonism, Augustinianism, and mystical influences derived from the works of pseudo-Dionysius. This fusion produced sometimes, notably in Scotus Eriugena, a pantheistic theory of the soul. All individual existence is but the development of the Divine life, in which all things are destined to be resumed. The Arabian commentators, Averroes and Avicenna, had interpreted Aristotle's psychology in a pantheistic sense. St. Thomas, with the rest of the Schoolmen, amends this portion of the Aristotelean tradition, accepting the rest with no important modifications. St. Thomas's doctrine is briefly as follows: the rational soul, which is one with the sensitive and vegetative principle, is the form of the body. This was defined as of faith by the Council of Vienne of 1311; the soul is a substance, but an incomplete substance, i. e. it has ...
