Prakriti as Material Cause
Prakṛti (Sanskrit: प्रकृति — from pra-kṛ, 'primary act, that which is made first') is the primal material nature — the underlying substrate of all non-conscious existence. It is the upādāna-kāraṇa (material cause) of the universe: all bodies, elements, sense organs, the mind (manas), intellect (buddhi), and ego (ahaṅkāra) evolve from prakṛti.
Prakriti and Achit
In Viśiṣṭādvaita, prakṛti is identified with achit (non-sentient matter) in its most fundamental form. Śaṅkara's school sees prakṛti as illusory (māyā); Madhva's school sees it as independent of God; Rāmānuja's Viśiṣṭādvaita holds that prakṛti is real, eternal, and Brahman's body — it exists within the Lord and depends on Him, not independently.
The Guṇas
Prakṛti operates through three qualities (guṇas): sattva (purity, clarity), rajas (passion, activity), and tamas (inertia, darkness). The interplay of these three guṇas drives all material creation, sustenance, and dissolution. The souls become entangled in saṃsāra when they identify with the guṇas of their material body-minds.
Transcending Prakriti
Liberation (moksha) involves the soul's disentanglement from identification with prakṛti — recognizing that 'I am not this body-mind, I am the ātmā, the Lord's eternal servant.' This does not annihilate the body or prakriti but restores the soul's awareness of its true nature as distinct from and transcendent of material nature.