The subject is what is lacking to knowledge. Knowledge in its presence, in its mass, in its own growth regulated by the laws which are different to those of intuition, which are those of the symbolic operation and of a close copulation of number with a real which is above all the real of a knowledge, this is what it is a matter of analysing in order to give the status, the true status of what is meant by a subject at the historical moment of science.
Just as all modern psychology is constructed to explain how a human being can behave in the capitalist structure, in the same way the true core of the research about the identity of the subject is to know how a subject sustains himself before the accumulation of knowledge. It is precisely this state, this extreme state, that the discovery of Freud offers to you, a discovery which means and which says that there is an “I think” which is knowledge without knowing it. That the link is quartered (écartelé) but at the same time tips over from this relationship of “I think” to “I am”. The one is *entzweiet* [split] from the other, there where I think, I do not know everything that I know, and it is not where I am discoursing, where I am articulating, that there is produced this announcement which is that of my being as being, from which I am being. It is in the stumblings, in the intervals of this discourse that I find my status as subject. The truth is announced to me where I do not protect myself from what comes in my word.
The problem of the truth re-emerges. The truth returns in experience and along a different path to that of my confrontation with knowledge, of the certainty that I may attempt to win in this very confrontation, precisely because I learn that this confrontation is ineffective, and that where I have a presentiment, where I avoid, where I divine one or other rock that I avoid, thanks to the extraordinarily rich and complex construction of a symptom, what I show as a symptom proves that I know what obstacle I am dealing with, alongside that, my thoughts, my phantasies construct, not alone as if I knew nothing about it, but as if I wished to know nothing about it. This is the *Entzweiung* [splitting]. The value of this image, the one that I put on the right, which is easy for you to reproduce because it is one of these constructions that one can make very simply by manipulating a strip of paper. It is still the Moebius strip but a Moebius strip that is in a way crushed and flattened.
I think that you will rediscover there the profile that I made familiar to you of the interval where in the interior eight there is knotted together the Moebius strip, namely, this strip which is stuck together again to itself after a simple half-turn and which has as a property, as I told you, this surface, of having neither a front nor a back, it is exactly the same.
Jacques Lacan 1964-65 Seminar 12: Crucial Problems for Psychoanalysis