Though he studied first medicine, then psychiatry, Lacan's influences are hardly orthodox Freudian. Like many French intellectuals who would become famous in the post-war period, Lacan also closely read Hegel's Phenomenology of Spirit. Moreover, he melded Hegel and Freud with structuralist anthropology and linguistics, game theory and topology into a forbiddingly complex body of work. Added to the difficulty such sources present, Lacan scholars often point to shifts in his long career at which he abandons heretofore important concepts and reconceives others. Further, his writing style suffers from an almost purposeful obscurity. Such factors prevent either easy or complete summary of Lacan's thinking.

Like Freud, Lacan focuses on the development of selfhood from the womb. Before we are born, the womb provides us unreflexive, uneventful well-being: the ‘pleasure principle’ reigns. Leaving the womb causes a rift between the feeling/demanding aspect of the organism and its biological drives, which strive to return it to the original happy state of quietude. We are born then with ‘a hole in the self’ even before a self can be fully formed. From our beginnings, we are never going to be able to be whole, autonomous selves, for we will always be ‘decentred’ owing to our unfulfillable desires, our essential ‘lack’. Worse, as infants, we don't really know what to desire; we must learn how to satisfy our needs through others. Desire, says Lacan, is always desire of the Other's desire; that is, we desire x only because we see an Other desiring x. The most important Other is, of course, our mother. We soon learn to desire what our mother desires not only because we know no better but because doing so attracts our mother's attention. In effect, we try to become a phallus - the major love object - for our mother. The ‘father’, however, thwarts our attempts, causing, both for boys and girls, ‘castration’ and Lacan's version of the Freudian Oedipus complex. Though painful, this intrusion of the ‘father’ helps us order our desires according to the same law that controls our mother's desires - the Law (or, as Lacan often says, the ‘name’) of the Father.

‘Castration’ then is the moment at which we become human beings, for the Law makes us ‘parle-être’ or speaking beings. Language from then on structures our desires: language comprises the Symbolic Order. We figuratively must ‘be told’ what we feel and think through the big Other, the arbitrarily and socially-constructed matrix of words, which is the active functioning of the Symbolic Order.

It is now relatively clear how Lacan might criticize the dominant western tradition which upholds the belief that language aids us in becoming thinking, autonomous persons. The major assumption of this Cartesian picture of subjectivity and language is precisely what Lacan intends to undermine, namely, that we use language to create ourselves. Lacan maintains that language uses us to create at most a social fantasy of unitary selfhood.

Even our unconscious lives are ‘structured like a language’. The unconscious often ‘speaks’ for repressed desires in slips of the tongue, jokes and other ‘parapraxes’ that are ‘symptoms’ of our split selves. Words, however, are constantly in flux and hence do not make good tools for representing or explaining our feelings or motives to ourselves. We are often faced with ‘little bits of the Real’, impossible events which cannot be ‘nailed down’ and therefore keep returning under different descriptions. Traumas, for instance, refuse symbolization and hence keep coming back to us as ‘impossible kernels’ of the Real. This last move of Lacan's - a version of Freud's ‘return of the repressed’ - forecloses any last comfort we might get from relying on language to make us whole.

Virtually all postwar European philosophical movements - deconstruction, Foucaultian genealogy, versions of French feminism, left Heideggerianism, Althusserian structuralism and, most recently, Slovenian psychoanalytic culture critique (most prominently Slavoj Žižek's) - have assimilated the Lacanian demolition of the unitary self. Even Anglo-American pragmatic and radical feminists have found it necessary to distance themselves explicitly from what they see as dangerous patriarchal tendencies in his approach. As a result, Lacan's critique of autonomy continues to maintain a significant presence decades after the master's death.