One thing, at least, I may presuppose that you know—namely, that psycho-analysis is a method of medical treatment for those suffering from nervous disorders; and I can give you at once an illustration of the way in which psycho-analytic procedure differs from, and often even reverses, what is customary in other branches of medicine. Usually, when we introduce a patient to a new form of treatment we minimize its difficulties and give him confident assurances of its success. This is, in my opinion, perfectly justifiable, for we thereby increase the probability of success. But when we undertake to treat a neurotic psycho-analytically we proceed otherwise. We explain to him the difficulties of the method, its long duration, the trials and sacrifices which will be required of him; and, as to the result, we tell him that we can make no definite promises, that success depends upon his own endeavours, upon his understanding, his adaptability and his perseverance. We have, of course, good reasons, into which you will perhaps gain some insight later on, for adopting this apparently perverse attitude. Now forgive me if I begin by treating you in the same way as I do my neurotic patients, for I shall positively advise you against coming to hear me a second time. And with this intention I shall explain to you how of necessity you can obtain from me only an incomplete knowledge of psycho-analysis and also what difficulties stand in the way of your forming an independent judgement on the subject. For I shall show you how the whole trend of your training and your accustomed modes of thought must inevitably have made you hostile to psycho-analysis, and also how much you would have to overcome in your own minds in order to master this instinctive opposition. I naturally cannot foretell what degree of understanding of psycho-analysis you may gain from my lectures, but I can at least assure you that by attending them you will not have learnt how to conduct a psycho-analytic investigation, nor how to carry out a psycho-analytic treatment. And further, if anyone of you should feel dissatisfied with a merely cursory acquaintance with psycho-analysis and should wish to form a permanent connection with it, I shall not merely discourage him, but I shall actually warn him against it. For as things are at the present time, not only would the choice of such a career put an end to all chances of academic success, but, upon taking up work as a practitioner, such a man would find himself in a community which misunderstood his aims and intentions, regarded him with suspicion and hostility, and let loose upon him all the latent evil impulses harboured within it. Perhaps you can infer from the accompaniments of the war now raging in Europe what a countless host that is to reckon with.