Index

In the passage from evans-dylan-an-introductory-dictionary-of-lacanian-psychoanalysis-taylor-francis, Lacan's "index" names a specific semiotic category borrowed from C. S. Peirce and deliberately repositioned within the Lacanian framework. Where Peirce contrasts the index with the icon and the symbol, Lacan redraws the boundary so that the index stands opposed primarily to the signifier. The index is defined as a 'natural sign': a sign in which the relationship between the sign and the object it indicates is fixed, necessary, and bi-univocal — one sign, one corresponding object, with no slippage. Smoke indexing fire is the paradigm case. Because the correspondence is determined by a real causal or co-presence relation rather than by differential positioning within a system, the index cannot be re-used across contexts to generate new or displaced meanings.

This contrasts sharply with the Lacanian signifier, which has no fixed or natural link to any one signified. The signifier is defined by its purely differential, relational character: it means only by not being other signifiers, and its "meaning effects" are produced retroactively through the chain rather than immediately from a coupling with an object. Accordingly, Lacan deploys the index/signifier opposition to sharpen two clinical-theoretical distinctions: (1) the medical symptom — a natural index of an underlying organic cause, readable according to a fixed code — versus the psychoanalytic symptom, which is a signifying formation structured like a language, encoding the subject's repressed desire; and (2) animal communication codes — closed, bi-univocal, and indexical — versus human language, which is irreducibly open, metaphorical, and governed by the primacy of the signifier.

Within evans-dylan-an-introductory-dictionary-of-lacanian-psychoanalysis-taylor-francis, "index" functions as a contrastive anchor — a theoretical foil that makes the distinctiveness of the Lacanian signifier and the psychoanalytic symptom legible. It is not an affirmative concept Lacan champions but a limit-case he defines in order to mark what human language and unconscious formations are not. In relation to the canonical concept of the Signifier (as synthesized above), the index represents precisely the fantasy of the stable sign: a unit with a fixed, natural coupling to a referent, untouched by the purely differential logic that governs the signifier. Where the signifier "has no fixed link with any one signified" and represents a subject for another signifier, the index bypasses subjectivity and the chain altogether, addressing the real directly.

In relation to the Symptom, the index/signifier distinction maps onto the medical/psychoanalytic divide: medical semiology reads symptoms as indices — fixed causal traces pointing to determinate organic states — while Lacanian clinical theory insists the symptom is a signifying formation, overdetermined and structured by metaphoric substitution, capable of being interpreted precisely because it is not indexical. The concept also quietly implicates the Language and Signification canonicals: the characteristic of human language that makes lalangue irreducible to a code — its equivocity, its metaphoricity, the endless referral of signification to more signification — is exactly what the closed bi-univocal index lacks. The "index" thus serves as the negative boundary concept that delimits, from the outside, the entire field defined by the interplay of signifier, signification, language, and symptom.

An Introductory Dictionary of Lacanian PsychoanalysisDylan Evans · 1996 (page unknown)

Lacan thus conceives the index as a 'natural sign', one in which there is a fixed, bi-univocal correspondence between sign and object (unlike the signifier, which has no fixed link with any one signified).

The phrase "fixed, bi-univocal correspondence" is theoretically loaded because it names precisely the semiotic closure — one sign, one object, no slippage — that the signifier is constitutively incapable of: the parenthetical contrast ("unlike the signifier, which has no fixed link with any one signified") encapsulates Lacan's entire reformulation of the Saussurean sign, in which the bar between signifier and signified is a structural resistance rather than a bond, making meaning an effect of differential relations rather than of natural attachment.