The Samkhya is the oldest of the orthodox philosophical systems in Hinduism postulating that the universe consists of two eternal realities such as the Purusha or the soul and the Prakriti or the matter or nature.

Being the silent spectators of Prakriti, the Purushas are many and are devoid of all qualities.
The Prakriti has three gunas or dispositions such as the sattvas, the rajas and the tamas.

The equilibrium of the gunas is disturbed due to the relationship of Purusha and Prakriti.

The Kaivalya or the liberation can be attained through the realization that the Purusha and the Prakriti are different. Thus Samkhya supports dualistic philosphy.