What kind of system requires cognitive defense mechanisms? If the self has no 'free' executive capability according to its own conception of what such freedom entails, it still has an inexplicable and counter-productive need to think well of itself and even to believe in its own freedom, at least to the extent that a great deal of energy is spent in maintaining its self-regarding illusions. Furthermore these defense mechanisms seem to inhabit a border region between the conscious and the unconscious; in so far as they must operate out of conscious purview - since their task is precisely to distort the conscious and pre-conscious account of the world - they are also vulnerable to conscious insight: if we are shown the defenses we are running it remains possible, although not inevitable, that our conscious understanding, indeed our entire world, will be modified to integrate this knowledge. One reason for the apparent need for such a structure might be that what is at stake are higher level constructs which form our motivational systems and that in order to function adequately these systems must remain relatively stable. This may be question-begging, but motivational stability would then then one of the reasons why experiences that might significantly affect self-referential value structures are heavily censored. Defense mechanisms are thus defined as cognitive loops that operate at every level to minimise or entirely prevent change. Another reason might simply be to prevent cognitive overload; feeling good about ourselves, believing we are free and holding on to a promise of happiness are thus heuristic goals which simplify the process of information filtering, and the self is the unique internal category which summarises this process. The real question underneath these speculations - and the function of 'truth' has not yet been considered - is why, if the self is merely a construct misrepresenting impersonal processes, it should take precisely the psychodramatic form that it does?