In his essay “The Mirror Stage As Formative of the Function of the I,” Lacan began a lifelong effort to rescue psychoanalysis from what he saw as a mistaken conflation of the subject and the ego. Instead of objectifying the ego as a mechanism that accommodates the libidinal instincts to the superego’s demands, Lacan posits the ego as an alienated reflection of the subject’s split sense of self, figured for him or her in the child’s perception of its own reflection. The child’s ego emerges as a conscious expression of the relation between an ideal self and a perceived self, and an ontological confusion results as the child’s ego attempts to structure its perceiving self in relation to its perceived image.

By understanding identity as a function of the alienating and distorting perceiver, Lacan cleared the way for his observation that the structural laws determining the unconscious operate according to the same linguistic laws on which Saussure based his theory of the sign. For Saussure, the linguistic sign was composed of a signifier and a signified—a phonetic sound and its concept. The relation between these two components of the sign is arbitrary but fixed, as may be seen by the simple fact that the same concept is expressed by different words in different languages (“tree” and “arbre,” for example). From this theory, Lacan posits an infinite sliding of the signifier from under the signified through the displacements and substitutions of metonymy and metaphor—the signifier operating like the alienated perceiver in the ego’s subject/object disintegration. Drawing on the analogy between the unconscious and language, Lacan argues that Saussure’s distinction between langue (language) and parole (speech) provides a model for understanding the structure of the unconscious. Against the entire field of possibilities that exist for any sentence, any particular act of speech exists as a tentative configuration of signifiers potentially sliding through a chain of associations. Thus, any signification is sustained only in reference to another signification to which the perceiver has not attended.

Recognizing that dreams disrupt such stability of signification, Lacan believes that in their structure the unconscious can be seen functioning similarly to the gestalt of language and speech: The dream acts as a sentence drawn from the symbolic language of the unconscious. The task of analysis, then, is to read the dream, finding through its associations the metonymies and metaphors that have been repressed in the sliding of the signifiers. It is these absences—rather than the presence of a specific theme representing some signified—that hold the key to the patient’s neurosis. Thus, just as language precedes and constitutes the social...

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