expressions peculiar to psychology (or more correctly: psychology of the deeper layers). Otherwise we should not be able to describe the corresponding processes at all, nor in fact even to have remarked them. The shortcomings of our description would probably disappear if for the psychological terms we could substitute physiological or chemical ones. These too only constitute a metaphorical language, but one familiar to us for a much longer time and perhaps also simpler. On the other hand we wish to make it quite clear that the uncertainty of our speculation is enhanced in a high degree by the necessity of borrowing from biological science. Biology is truly a realm of limitless possibilities; we have the most surprising revelations to expect from it, and cannot conjecture what answers it will offer in some decades to the questions we have put to it. Perhaps they may be such as to overthrow the whole artificial structure of hypotheses. If that is so, someone may ask why does one undertake such work as the one set out in this article, and why should it be communicated to the world? Well, I cannot deny that some of the analogies, relations and connections therein traced appeared to me worthy of consideration.[36] VII If this attempt to reinstate an earlier condition really is so universal a characteristic of the instincts, we should not find it surprising that so many processes in the psychic life are performed independently of the pleasure-principle. This characteristic would communicate itself to every part-instinct and would in that case concern a harking back to a definite point on the path of development. But all that the pleasure-principle has not yet acquired power over is not therefore necessarily in opposition to it, and we have not yet solved the problem of determining the relation of the instinctive repetition processes to the domination of the pleasure-principle. We have recognised that one of the earliest and most important functions of the psychic apparatus is to ‘bind’ the instreaming instinctive excitations, to substitute the ‘secondary process’ for the ‘primary process’ dominating them, and to transform their freely mobile energy-charge into a predominantly quiescent (tonic) charge. During this transformation no attention can be paid to the development of ‘pain’, but the pleasure-principle is not thereby annulled. On the contrary, the transformation takes place in the service of the pleasure-principle; the binding is an act of preparation, which introduces and secures its sovereignty.