In the non-dual Trika philosophy of Kashmir Shaivism, the tattvas are 36 principles describing how reality unfolds from pure consciousness (Shiva) down to gross matter (earth). They extend the 25 tattvas of the older Samkhya system by adding eleven higher principles.
They’re usually grouped in three tiers: the five pure (shuddha) tattvas of universal consciousness; the seven pure-impure (shuddha-ashuddha) tattvas, where limited individuality and the “five sheaths” emerge; and the twenty-four impure (ashuddha) tattvas of mind, the senses and materiality. The scheme maps a descent from unity into apparent multiplicity, which yogic practice retraces in reverse, toward recognition of one’s identity with Shiva.