Samkhya philosophy postulates two realities out of which all things evolve:purusha, spirit principle and consciousness, and prakriti, nature principle, energy and matter. In Sanskrit pur means city and sha means sleep; purusha means 'that which sleeps in the city'. In this sense purusha is the dormant receptacle of consciousness, the totality of consciousness. This consciousness is knowledge and contains nothing but knowledge. Consciousness is the faculty of awareness in the human mind. The word prakriti is composed of pra, a semantic prefix in Sanskrit, and kriti, action. This refers to prana which is the active principle of the manifested energy. Consciousness is dormant; prana is active. Neither can exist or function without the other. Prana is an active force without knowledge to direct or will. Consciousness is knowledge without motion to give realization.
The Prashnopanishad clearly states that there are two aspects of being : prana and consciousness. These two aspects of cosmic energy represent two totally different forces in the cosmos and the human body. The opening paragraph of Ananda Lahiri by the sage Shankaracharya states:
"Is it possible for Purusha to create, to act, to manifest, to express, to dissolve, to maintain the object and the creation without the help of Prakriti? Shiva without Shakti? Matter without energy? Purusha without Prakriti is incapable of expression, manifestation and absolute motion."
Cosmic prana, mahaprana, and supreme consciousness, paramatman, represent the real universe, and when combined they are called Brahma, God, Allah, etc.
Practically speaking, it is very difficult to differentiate between prana and consciousness. Consciousness is being. Prana is not the cause, nor is consciousness the result. Neither is consciousness the cause, nor prana the result. They are the two aspects of existence which determine the nature of everything. Purusha, as awareness or consciousness, has the potential to move but in itself is inert. Prakriti, as prana, is manifest in everything. It has the power of working, but not on its own. The union of purusha and prakriti, or the investing of consciousness with prana, results in action.
Samkhya uses the analogy that purusha can see but cannot walk, whereas prakriti can walk but cannot see. In the tantric texts, prana is symbolized as the feminine principle and consciousness as masculine. This is the basis for the concepts of Shiva and Shakti and the Vedantic and Puranic conception of gods and goddesses. Shiva is always accompanied by his consort. The female characteristics of the consort are conceptualised in many forms such as Kali, Durga, Parvati, Uma etc. in human incarnations. Similarly, the other gods are depicted with their shakti or consort; for example, Brahma and Saraswati, and Vishnu and Lakshmi. These are all meant to draw attention to the same philosophical concept of polarity, which is best illustrated by male and female, consciousness and prana.
This polarity principle is responsible for the manifest universe. Prana and consciousness are separate entities existing in duality, but ultimately are opposite manifestations of the same force. Consciousness and prana are the positive and negative elements of the one inconceivable force which is responsible for everything that takes place in the individual and cosmic life.