Conjectural Science

Conjectural science names a distinct epistemological category that Lacan opposes both to the exact or natural sciences and to the so-called "soft" or human sciences. The theoretical move is precise: psychoanalysis, cybernetics, game theory, and related disciplines share a common structural problem — the problem of chance, determinism, and the order that can be extracted from contingency through formal operations on symbols and language. In Seminar II (p. 302), Lacan proposes "conjectural sciences" as the proper name for what is habitually and inadequately called the "human sciences," stressing that conjecture is not mere probability or vagueness but can be "ordered into certainty" through strategy. The shared axis uniting psychoanalysis and cybernetics within this category is language itself: both operate at the level of discrete symbolic elements whose combinations are governed by structural laws, and both are concerned with how chance sequences become regularized into reproducible patterns. A conjectural science does not measure natural objects or produce laws of nature; rather, it formalizes the structure of symbolic operations under conditions of uncertainty.

The critical bite of the concept emerges from what it refuses. It refuses, on one side, the reduction of psychoanalysis to a natural or biological science — which would dissolve the specificity of the drive (irreducible to instinct) and the unconscious (irreducible to neural or adaptive process) into empiricist measurement. On the other side, it refuses alignment with the "soft" sciences understood as disciplines that accept imprecision as their lot. Instead, conjectural science occupies a third position: its objects are symbolic and linguistic, its methods structural and formal, and its results can — by way of strategy and formalization — achieve the force of necessity within their own domain. This directly underwrites Lacan's critique of ego psychology: by aligning psychoanalysis with the exact or positive sciences (as ego psychology implicitly does in its biologistic and adaptive framework), one loses precisely what is scientific about it — its capacity to formalize the symbolic order of the unconscious.

The concept appears in two sources: jacques-lacan-seminar-2 (p. 302), where it is coined as the preferred name for a group of disciplines currently mislabeled "human sciences," and derek-hook-calum-neill-stijn-vanheule-reading-lacan-s-ecrits-from-the-freudian-t, where it is deployed in the context of Lacan's critique of ego psychology and his structuralist alignment of psychoanalysis. In both occurrences, the concept is doing the same work: carving out a specific epistemological niche for psychoanalysis that distinguishes it from both positivist science and interpretive vagueness.

The concept is best understood as an extension and specification of the cross-referenced canonical of Structuralism. Where structuralism grounds meaning in differential, symbolic relations rather than natural positive facts, conjectural science generalizes this move epistemologically: it names the kind of science that is adequate to symbolic, linguistic, and combinatory objects — i.e., the kind of object structuralism studies. At the same time, it directly confronts Ego Psychology, which implicitly assimilates psychoanalysis to the natural-scientific or adaptive-biological model; by insisting psychoanalysis is conjectural rather than exact or positive, Lacan defends the irreducibility of the Unconscious (structured like a language, not a natural system) and of the Drive (distinct from instinct) to any biologistic reduction. The Analysand's free-associative speech, the primary material of psychoanalytic practice, is precisely the kind of symbolic-contingent data that a conjectural science formalizes — not measured, but strategically ordered into structural certainty.

Reading Lacan's Écrits: From 'The Freudian Thing' to 'Remarks on Daniel Lagache'Derek Hook, Calum Neill & Stijn Vanheule (eds.) · 2019 (page unknown)

psychoanalysis is not aligned with exact, natural, 'positive' sciences... but with the conjectural, speculative, sciences like game theory or cybernetics. This position should not be confused with an alignment with the 'soft' sciences: 'For conjecture is not the improbable: strategy can order it into certainty'

The phrase "strategy can order it into certainty" is theoretically decisive: it names the specific mechanism — formalization through symbolic strategy — by which a conjectural science overcomes mere probability without collapsing into the determinism of natural science. The contrast between "conjecture" (symbolic, structural, operating on chance) and "improbable" (merely statistical or underdetermined) marks the exact epistemological distance Lacan is defending for psychoanalysis.