... [T]he unconscious, as the name suggests, is precisely that region of mental life to which consciousness has no ready access. As such, it is inaccessible to positive description. Freud’s statement that its processes ‘show characteristics which are not met with again in the system immediately above it’ might be restated thus: unconscious processes cannot be captured in the language of conscious ones.
... Take the first ‘special characteristic’ of the unconscious Freud identifies: ‘it consists of drive-representatives [Triebrepräsentanzen] which seek to discharge their cathexes; that is to say, it consists of wishful impulses’. In less technical terms: the unconscious is the domain of the unrestricted pleasure principle, an underground cavern of drives demanding perpetual satisfaction, drives so imperious they are oblivious to one another’s presence: ‘Drive impulses ... exist side by side without being influenced by one another, and are exempt from mutual contradiction’. The dry, quasi-scientific vocabulary can’t conceal—indeed only accentuates—the disturbing indeterminacy of the object it describes. Freud employs the authoritative tone of the man of science to delineate an entity beyond the reach of direct classification and observation.
How, then, are we to understand a force that violates (common) sense? A proverbial illustration may be helpful: I can of course desire both to have my cake and to eat it. But to be conscious is to know that discharging one of these desires cancels out the other. The unconscious does not know this: its desires both to possess and to consume the cake can exist side by side, blissfully impervious to their basic incompatibility. In the unconscious, I eat my cake and continue to demand I have it—not however, another cake, but precisely that cake, the one I’ve eaten.