This thesis explores questions which have vexed both philosophers and sociologists. These are questions which, to varying degrees remain unanswered, but which, nonetheless, are basic questions pertaining to our existence. Just what is the nature of the 'subject'? Can we even say that the 'subject' exists? What is consciousness? What role does language play in defining the subject? What is 'truth'? Is there a 'truth'? How much autonomy does the subject have? The main question, though, posed in this thesis relates to whether we are: Prisoners of our own Consciousness? It is from a reading of the writings of certain late twentieth century French thinkers that the above questions are considered. The four writers: Jean Paul Sartre, Michel Foucault, Jacques Derrida and Pierre Bourdieu, offer their views. Whilst Jean Paul Sartre advocates atheistic existentialism, the remaining three French theorists have been labelled post-structuralists, a term given, rather than claimed. Whilst Sartre, Foucault, Derrida and Bourdieu have differing views on the above questions, there are points of congruence. The elusiveness of the subject is one such point of agreement. There is also agreement amongst the four (less overtly expressed by Derrida) that freedom of the subject is a possibility. For Sartre, freedom is the very essence of humankind. The thinkers differ on the matter of 'truth'. Sartre believes in an absolute truth. Foucault deals with 'regimes of truth'. Derrida remains somewhat silent, except that he contends there is a justice, which does not exist but which is an ideal and is infinitely irreducible. Bourdieu unashamedly believes all scientists are seeking the truth, and he proposes a method which he believes will assist in the pursuit of that goal. Each of the four theorists contends, to some degree, that language and discourse are constructed by the social world and influence our perception of reality. Regarding the notion of being 'prisoners of our own consciousness?', the theorists under scrutiny, with the exception of Sartre, believe we are seriously constrained by language and discourse. Foucault and Bourdieu are of the opinion that knowledge may free us from this predicament. I suggest that humankind is neither free, nor non-free. Rather, that the 'subject' merely Is. I suggest that we are not prisoners because to endorse such a view, would be to accept that we are being detained from a realm which would be our 'normal' realm. Given that there is no realm other than the present, and given that constraints are consistent with the nature of humankind, we cannot be said to be prisoners. Further, it is argued that not only our consciousness defines us but also our unconsciousness. And both consciousness and unconsciousness, in turn, are defined by the social world in which we live.