Epoché and the Transcendental Reduction

Husserl's methodical operation of abstention (Greek ἐποχή, "suspension of judgment"): a deliberate putting-out-of-play of the natural belief in the world, which makes possible the transcendental reduction — the disclosure of the world purely as the correlate of the subjectivity that constitutes it. In the *Crisis* the epoché is reached by a new path (inquiring back from the life-world) rather than by the "Cartesian way" of the Ideas, and it is performed not piecemeal but "with one blow."

False-friend caution. Husserl's epoché (ἐποχή, suspension) is etymologically and conceptually unrelated to Péguy's époque on period-vs-epoch (a mode of historical-political time). Do not cross-link them despite the shared "epoch" string.

Key Points

Two epochés in Descartes and Husserl. The Cartesian epoché has "hitherto-unheard-of radicalism" — it brackets not only the sciences but the pre-scientific world — yet Descartes does not sustain it and "psychologistically falsifies" its result (the pure ego becomes the soul). Husserl's transcendental epoché is its genuine fulfilment (§§17–18).
First step vs. total epoché. The first step brackets the objective sciences (suspending all participation in their cognitions), but this is insufficient — one still stands "on the ground of the world." The total epoché "puts out of action, with one blow, the total performance" of natural world-life; carried out piecemeal "it cannot lead to the goal" (§§35, 39–40).
A "religious conversion." The epoché is "a complete personal transformation … comparable in the beginning to a religious conversion," a habitual attitude "resolved once and for all" (§35) — the "total change of the natural attitude of life" (§39; see natural-attitude).
The reduction discovers, it does not interpret. What the epoché frees us from is "the strongest … most hidden internal bond, namely, the pregivenness of the world"; what it discloses is "the universal, absolutely self-enclosed … correlation between the world itself and world-consciousness." Husserl insists: "This is not a 'view,' an 'interpretation' bestowed upon the world" (§41) — the contested, arguably question-begging move.
The a priori of correlation. The reduction's master finding: every object is given only through subjective "manners of givenness," structured by horizon and by retention–protention; "anything that is … is an index of a subjective system of correlations" (§48). Husserl's famous footnote dates the first breakthrough of this correlation-a-priori to ~1898 and says it has dominated his whole life-work (§48).
The new way beats the Cartesian way. The Cartesian way "leads to the transcendental ego in one leap … apparently empty of content," tempting a relapse into the natural attitude; the life-world way supplies the missing preparatory explication (§43).

What the Concept Does

The epoché is the threshold operation of transcendental phenomenology: it is what converts the world from a ground one stands on into a phenomenon one studies. Without it, every analysis of consciousness remains mundane (psychological); with it, the constituting correlation becomes thematic. In the Crisis its specific work is to make the life-world's pregivenness — normally invisible because universal — into a problem, and thereby to open the "new dimension" of depth beneath the "plane" of natural and scientific life (§§29, 32).

What It Rejects

Cartesian methodical doubt as a piecemeal withholding of individual validities — which only "creates for each instance a new mode of validity on the natural ground of the world" (§40).
The psychologistic misreading of the reduction's residue (Descartes's soul; any "scientific psychology") — within the epoché "a pure soul has no meaning … except as phenomenon" (§18).
The foundationalist misreading of the ego cogito as "a premise … from which the rest of knowledge was to be deduced" — "The point is not to secure objectivity but to understand it" (§55).

Stakes

If the epoché is genuinely total, the world's existence is neither affirmed nor denied but suspended as a question, and philosophy "begins without any underlying ground," creating its ground "through its own powers" (§53). The cost is severe: the epoché creates a "philosophical solitude" (the primal ego) and, by Merleau-Ponty's reading of these very texts, may be impossible to complete ("the most important lesson of the reduction is the impossibility of a complete reduction," PhP Preface) — a thesis MP draws from Husserl's own admission that one "can never again achieve the old naïveté" (§59). (Confidence: high for Husserl; the incompleteness thesis is MP's.)

Connections

requires natural-attitude — the epoché is precisely the "total change" of the natural attitude.
discloses lebenswelt — the first step reduces to the life-world; the total epoché reaches the constituting correlation above it.
makes possible the paradox-of-human-subjectivity — the reduction's residue is the constituting (primal) ego.
is fulfilled against Descartes's unsustained epoché and self-misinterpretation (§§17–18).
has inverted-vector cousin haptico-transcendental-reduction — Derrida/Nancy reduce sense to touch (a life-world sense-modality), where Husserl's reduction moves away from sensible givenness toward constituting subjectivity.
is read as incompletable by maurice-merleau-ponty — the late-MP "réduction de la réduction."

Open Questions

Is §41's insistence that the reduction "is not a 'view'" defensible, or does making the world a correlate of subjectivity already enact the idealist interpretation it disavows?
How does the "with one blow" total epoché stand to the step-by-step presentation Husserl nonetheless gives (first step → total)? Is the staging pedagogical or substantive?

Sources

husserl-1954-crisis — §§17–19 (the Cartesian epoché and its falsification); §35 (first step; "religious conversion"); §§39–43 (total epoché; the new way vs. the Cartesian way); §46, §48 (the a priori of correlation; the ~1898 footnote); §55 (the second epoché; against the "Cartesianism" misreading); §59, §72 (psychology before/after the reduction; Einströmen).