 The Preface to Phenomenology of Perception, completed after the main text, offers Merleau-Ponty’s most detailed and systematic exposition of the phenomenological method. His account is organized around four themes: the privileging of description over scientific explanation or idealist reconstruction, the phenomenological reduction, the eidetic reduction, and intentionality. Phenomenology sets aside all scientific or naturalistic explanations of phenomena in order to describe faithfully the pre-scientific experience that such explanations take for granted. Similarly, since the world exists prior to reflective analysis or judgment, phenomenology avoids reconstructing actual experience in terms of its conditions of possibility or the activity of consciousness. The phenomenological reduction, on his interpretation, is not an idealistic method but an existential one, namely, the reflective effort to disclose our pre-reflective engagement with the world. Through the process of the reduction, we discover the inherence of the one who reflects in the world that is reflected on, and consequently, the essentially incomplete character of every act of reflection, which is why Merleau-Ponty claims that the “most important lesson of the reduction is the impossibility of a complete reduction” (PP: 14/lxxvii). Similarly, the “eidetic reduction”, described by Husserl as the intuition of essential relations within the flux of conscious experience, is necessary if phenomenology is to make any descriptive claims that go beyond the brute facts of a particular experience. But this does not found the actual world on consciousness as the condition of the world’s possibility; instead, “the eidetic method is that of a phenomenological positivism grounding the possible upon the real” (PP: 17/lxxxi). Lastly, Merleau-Ponty reinterprets the phenomenological concept of intentionality, traditionally understood as the recognition that all consciousness is consciousness of something. Following Husserl, he distinguishes the “act intentionality” of judgments and voluntary decisions from the “operative intentionality” that “establishes the natural and pre-predicative unity of the world and of our life” (PP: 18/lxxxii). Guided by this broader concept of intentionality, philosophy’s task is to take in the “total intention” of a sensible thing, a philosophical theory, or an historical event, which is its “unique manner of existing” or its “existential structure” (PP: 19–20/lxxxii–lxxxiii). Phenomenology thereby expresses the emergence of reason and meaning in a contingent world, a creative task comparable to that of the artist or the political activist, which requires an ongoing “radical” or self-referential reflection on its own possibilities. On Merleau-Ponty’s presentation, the tensions of phenomenology’s method therefore reflect the nature of its task: 