[56] who was always studying that knowledge which is conversant about the body and vain opinions, not being able to rule and govern irrational nature (for it is customary for old [15] [16] men to be appointed to offices of irresponsible authority; but this man is always young, even if after a lapse of time he may come to support old age, which has at last reached him); and being accustomed to nourish this and to lead it on to growth, he expects to be able to persuade the lovers of virtue to change and come over to him, in order that in so changing to irrational and inanimate objects, they may have no leisure for applying themselves to the studies of a rational soul.