Tattva, from tat (“that”) plus the suffix -tva (“-ness”), means literally “thatness” — the essential nature or irreducible category of a thing. In Indian philosophy the word names something more technical than an ordinary object: a tattva is one of the fundamental principles or levels of reality through which consciousness is said to condense into the manifest world. Samkhya, Vedanta, and the Tantric traditions of Kashmir Shaivism each work with their own count and ordering of tattvas, but all agree that reality does not appear as a single undifferentiated block — it unfolds through a defined sequence of stages.
Samkhya’s classical scheme lists twenty-five tattvas, beginning with Purusha, pure witnessing consciousness, and Prakriti, primordial nature, and tracing Prakriti’s evolution outward through mahat (cosmic intelligence), ahamkara (the ego-sense), manas (mind), the five sense faculties, the five faculties of action, the five subtle elements or tanmatras, and finally the five gross elements. Kashmir Shaivism extends the count to thirty-six, adding eleven further tattvas above Purusha and Prakriti to trace existence back through layers of contraction to Shiva and Shakti themselves — undivided consciousness and its power to manifest.
Practically, a map of tattvas functions as a route rather than a museum catalogue. Tantric and yogic meditation often works by systematically withdrawing identification from the grosser tattvas — body, senses, mind, ego — back through the subtler ones, retracing the very sequence by which consciousness is said to have condensed into form. This technical sense of tattva sits comfortably beside its everyday use in Hindi and other Indian languages, where tattva simply means “essence” or “truth”: to know the tattvas of a thing, in either sense, is to know what it most fundamentally is.