“I’ll be concerned in the following with connecting repression (or, more precisely, primal repression) to the drives (or instincts), using the 1915 essays “Instincts and Their Vicissitudes” and “Repression.” I hope I got it all (somewhat) right!
Primal repression is the fate (vicissitude) of a drive whose aim is not satisfaction but an increase in pain—that is, repression is what happens when the aim of the drive is changed into one of seeking unpleasurable satisfaction. Or, since we can’t really speak of such an aim (the aim of a drive is always satisfaction, and satisfaction is precisely pleasure, so there cannot be a drive whose aim is unpleasure), we have to say that repression is what happens when the pleasure of an instinct’s satisfaction also causes an experience of unpleasure.
Freud rules out the idea that this confluence of pleasure and unpleasure in the aim of the drive—this vicissitude—is merely one that is occasioned by having satisfaction delayed for a long time: repression is not just the result of the drive getting confused about what satisfaction is (as it were), creating more and more tension to the point where the satisfaction itself would still not be pleasurable. This is an important counterexample, because it sets up an idea of different localizations of pleasure and unpleasure rather than one homogenous psychic experience of them.
That is, he proposes that the satisfaction is unpleasurable in a different part of the mind than where the satisfaction itself goes on: this is how the satisfaction of the drive can be a satisfaction (a pleasure on some level) and unpleasurable (on some other level) at the same time (so to speak). The unpleasure then is merely the irreconcilability of satisfaction with some other parts of the mind (it is the agent of psychic differentiation, therefore—see below).
So this means that repression is correlated with the development of the consciousness and unconscious. That part of the mind in which the drive would be satisfied is the unconscious, and that part of the mind that would experience the unpleasure—that is, a satisfaction that only increases tension—is consciousness. Primal repression differentiates the two, allowing for the formation of a set of structures (ideas) within the unconscious that are developed more and more without direct relation to their unpleasurable effect. The unpleasurable effect can then be dampened by counter-formations, or “repression proper,” so that when one of these drives (or representatives of the drives, Freud shifts his view on this) appears, it can be satisfied and, at the same time, its unpleasurable effects avoided. That is, the idea that the drive is associated with can become represented in consciousness (though in a distorted fashion), without its unpleasurable affect (that is, its effect). Thus Freud will say the affect is what is subject to repression and the idea remains—both in the unconscious and (in the distorted form) in consciousness.
To inscribe this back into the problematic with which Freud started is the toughest part (Freud himself doesn’t exactly do it explicitly), but which, when done, gives the full sense of the importance of repression for Freud. The organism deals with drives by transforming its world. This is because drives are excitations or pressures that the organism must get rid of (according to the principal of constancy). In the case of the repressed drive, we have an inability of the organism to transform its world, to act on the outside and thereby get rid of the tension. In fact, getting rid of the tension (letting the drive satisfy itself) would precisely cause pain, or more tension. So the organism turns inward and divides itself up instead. The result is that it transforms its world by transforming itself: it transforms the world by constructing the world for itself in which it can, at the same time, 1) answer to the demands of the drives that are repressed (by repression proper, distortion, etc.) and 2) deal with other drives (by acting on the world). This theme of inner psychic differentiation is present all throughout Freud, from the Project to the odd crust he thinks about in Beyond the Pleasure Principle.”—