In Hinduism, Avyakta literally means not manifest, cannot be experienced by the sense organs. In the Samkhya system, the word avyakta indicates prakriti (primordial nature or matter), which is said to be the first, or primary cause of all existence, of the material world. They are all said to be the evolutes of the avyakta. Samkhya is a dualistic system based on two basic realities – energy and matter.
Avyakta is also called alinga, because it is not itself the
product or effect of anything else, and so it has no linga, or cause. It is
called mulaprakriti, because it is the first cause of all else, except of the
selves. It is also given the name pradhana because in the material world it is the
main, the chief, among the existents.
Avyakta, as explained in Samkhya Karika (10-11), is
constituted by three gunas, namely sattva, rajas, and tamas. It is jada (a
material principle). It exists not for its own sake, but for the purushas
(selves). It is all pervading and omnipresent. It gives rise to modified forms
of itself, according to the doctrine called Parinamavada. First there is
tattvantraparinama in which 23 tattvas emerge in a particular order, and
further there are three parinamas (modifications) undergone by all manifest
objects of experience. They are respectively called dharma parinama, lakshana
parinama and Avastha. In Samkhya, the existence of avyakta as the first cause is
proved on the basis of Satkaryavada.