The Hindu philosophy is categorized into six Orthodox and three Heterodox philosophies. The classification is based on the acceptance of the authority of the Vedas. The Orthodox school of philosophy also called the Aastika school believes in the authority of Vedas, while the Heterodox school of philosophy, popularly known as Nastika school rejects the principle of authority of Vedas.
Six Orthodox Schools of Hindu Philosophy
The six orthodox schools are called as shatdarshanas and include Nyaya, Sankhya, Yoga, Vaisheshika, Purva Mimamsa and Uttara Mimamsa (Vedanta Philosophy). Most of these schools of thought believe in the theory of Karma and rebirth. Moksha (salvation) is believed to be the liberation from the cycle of birth and death and is the ultimate goal of human life.
Nyaya school follows a scientific and a rational approach. Sage Gautama is the founder of this school. Nyaya school banks upon various pramanas (mechanism of attaining knowledge). It believes that gaining knowledge through the five senses is the sole way of attaining liberation from the cycle of birth and death.
Sankhya is the oldest of all philosophies put forth by the sage Kapila. It is a dualistic philosophy with Purusha (soul) and Prakriti (nature) in it. Advaita Vedanta derives its base from Sankhya School. Sankhya also devolves philosophical basis for Yoga. It emphasizes the attainment of knowledge of self through meditation and concentration.
Yoga school introduces the methods of the discipline of body and mind. Sage Patanjali is the founder of Yoga. Emancipation of Purusha from Prakriti by self-awareness through the discipline of body and mind is conceptualized by Yoga. It is believed that practising Ashtanga Yoga is the way to relieve oneself from past sins in order to make way for liberation.
Vaisheshika school deals with metaphysics. It was founded by the sage Kanada. It is an objective and realistic philosophy of the Universe. According to the Vaisheshika school of philosophy, the universe is reducible to a finite number of atoms, Brahman being the fundamental force causing consciousness in these atoms.
Purva Mimamsa school believes in the complete authority of Vedas. It is based on sage Jaimini’s Mimamsa Sutras. It emphasizes the power of yajnas and mantras in sustaining the activities of the universe. It states that a human being can attain salvation only by acting in conformity with the principles of Vedas.
Uttara Mimamsa (Vedanta)
Vedanta school is a monistic school of philosophy that believes that the world is unreal and the only reality is Brahman. The three sub-branches of Vedanta are Advaita of Shankaracharya, Vishishta Advaita of Ramanujacharya and Dvaita of Madhwacharya. Uttara Mimamsa is based on Upanishads (the end portions of Vedas).