In Samkhya philosophy, the concept of self is viewed as a separate entity from the physical body and the material world. This concept of self is known as Purusha, which is often translated as spirit or consciousness. According to Samkhya, Purusha is the ultimate reality and the source of all consciousness and intelligence.

Purusha is seen as eternal, unchanging, and unaffected by the material world. It is pure consciousness, devoid of any qualities or attributes. It is the witness and observer of all experiences, but it does not participate or get affected by them. This concept of self is similar to the concept of Atman in Hinduism and the concept of soul in other religious traditions.

On the other hand, Prakriti is the material world, which is made up of three gunas or qualities – sattva (purity), rajas (activity), and tamas (inertia). Prakriti is constantly changing and evolving, and it is the source of all physical and mental phenomena. It is through the interaction of Purusha and Prakriti that the world of experience is created.

Samkhya philosophy sees the self as fundamentally different from the body and the mind. The body and the mind are considered as part of Prakriti, and they are subject to change and decay. However, Purusha remains eternal and unchanging, even after the death of the body.

Furthermore, Samkhya also distinguishes between individual self (jivatman) and the universal self (paramatman). Jivatman is the individual self, which is associated with a particular body and mind. It is the individual's sense of "I" or ego. Paramatman, on the other hand, is the universal self, which is present in all beings and is the same as Purusha. It is the ultimate reality that connects all beings and is the source of all existence.

In summary, Samkhya views the concept of self as a dualistic reality between Purusha and Prakriti. Purusha is the eternal, unchanging, and pure consciousness, while Prakriti is the constantly changing material world. This concept of self is essential to understand the nature of existence and the relationship between the individual and the universe.