Purusha and Prakriti: Consciousness and Nature Are Two Irreducible Principles

The Samkhya school builds its entire account of reality on a single, uncompromising division: consciousness and matter are two genuinely separate and irreducible principles, and nothing in the system allows one to turn into or be explained by the other. Purusha, pure consciousness, does nothing at all; it only witnesses, silently and without acting, everything that unfolds before it. Prakriti, unconscious nature, does everything else, unfolding on its own, without any guiding will, into mind, ego, the senses and the physical elements the material world is made of, driven by the interplay of three qualities called gunas, lightness and clarity, activity and passion, and inertia and darkness. Ishvarakrishna's Samkhyakarika, composed in a spare seventy two verses around the fourth or fifth century, systematized this scheme into twenty five fundamental principles, or tattvas, purusha standing as the twenty fifth and final one, the silent witness for whose sake the other twenty four, all products of prakriti alone, are said to exist and unfold in the first place. What the manifest world actually is, on this account, is nothing more than prakriti being observed, a claim of two irreducible principles held together, one wholly passive and one wholly active, neither one ever collapsing into or explaining the other.

Samkhya is counted among the oldest of classical India's six systems of philosophy, and its account of purusha and prakriti supplied the metaphysical foundation an entirely different school later built a practical discipline on top of. The Yoga system associated with Patanjali adopts Samkhya's dualism of consciousness and nature almost without alteration, accepting the same twenty five tattvas and the same picture of prakriti unfolding into mind and matter while purusha stands apart from it as pure witness. Where Yoga departs from its source is in adding a twenty sixth element missing from classical Samkhya entirely: Ishvara, a particular, distinguished form of purusha untouched by affliction, action or its results, who serves in the Yoga system as an object of devotion and a support for meditative concentration rather than as a creator god responsible for the universe's existence. Classical Samkhya itself has no need of such a figure and no settled position on whether one exists, since liberation in its own system comes purely through discriminating knowledge, the direct recognition that one is purusha and not prakriti, with no divine assistance required to reach it. That difference marks the clearest line between the two schools even as Yoga otherwise inherits Samkhya's picture of the cosmos nearly whole, which is why the two are so often described as a paired philosophy rather than as two unrelated systems that happen to share some vocabulary.