I Am grateful for the honour of being invited to give the second Manson Lecture. Dr. Manson believed that the study of sick people leads into the widest fields of thought, but that increasing specialization within medicine diverts the doctor from seeing man and his nature whole: the chief question seems to be (he wrote in 1930), “whether medicine is in the bondship of practice, whether it is a skilled art, or whether it can emerge to give its own contribution to abstract thought and philosophy.” Indeed, pleading with doctors to join this Institute of Philosophy, he declared that medicine should be the most philosophic of the professions. In this he was reviving an ancient claim: the arguments for it have lately been restated with much Aristotelian piety by Scott Buchanan. Now here I find myself in a difficulty at the outset: I am to speak of the relationship between philosophy and medicine, at a lecture founded by a passionate believer in their conjunction, yet I am engaged in a particular branch of medicine which was for longer than any other preoccupied with philosophy and dependent on it, but had so little profit from its fidelity that it reckons progress from the time when it struggled away from this allegiance. Psychiatry has not been able to refrain since then from many a backward glance at the older philosophy she once swore by, and she has been much influenced by the philosophies of later times: she has—doubtless in punishment for her defection—become entangled now and then in bad, unrecognized philosophy of her own making. She has, at all events, never achieved more than a temporary indifference to philosophic thought.