We should think of the most authoritative part of our soul as a guardian spirit given by god, living in the summit of the body, which can properly be said to lift us from the earth towards our home in heaven; for we are creatures not of earth but of heaven, where the soul was first born, and our divine part attaches us by the head to heaven, like a plant by its roots, and keeps our body upright. If therefore a man’s attention and effort is centred on appetite and ambition, all his thoughts are bound to be mortal, as it is his mortal part that he has increased. But a man who has given his heart to learning and true wisdom and exercised that part of himself is surely bound, if he attains to truth, to have immortal and divine thoughts, and cannot fail to achieve immortality as fully as is permitted to human nature; and because he has always looked after the divine element in himself and kept his guardian spirit in good order he must be happy above all men. (Timaeus)
