Indian philosophy was classified by the ancients into two types: the orthodox schools of thought and the unorthodox (or heterodox) schools of thought. The key distinguishing factor is that the six orthodox schools acknowledge the revealed scriptures (the Vedas, especially the Upanishads) and often the other scriptures also (especially the Bhagavad Gita), while the unorthodox schools do not. The unorthodox schools include Buddhism, Jainism, and the Charvaka school (atheist materialists who believed that the physical universe was all that existed; this doctrine was called Lokayata).
The six orthodox schools of Indian philosophy are often listed in pairs, and they are: Nyaya and Vaishesika, Mimamsa or Purva Mimamsa and Vedanta, and Sankhya and Yoga. Although all six accept the Vedas, only Mimamsa and Vedanta draw their philosophy from these scriptures. The other four are based largely upon independent reasoning.
The
Nyaya and
Vaishesika are closely related schools concerned more with logic and epistemology than Scriptural revelation or salvation.
The Nyaya school was formed by Gautama, author of the Nyaya Sutras. The word Nyaya means "that by which the mind is led to a conclusion." This philosophy holds that the soul is distinct from organs of sensation, organs of action, and from the mind. Judgements and actions are transitory, but have more permanent effects as Karma, which affects the soul's union with the body, and rebirth. Ethical action consists in avoiding the "three defects": attachment (which comes from lust, jealousy, avarice, and covetousness), misconception (which comes from wrong apprehension, suspicion, pride, and negligence), and aversion (which comes from anger, envy, malice, hatred, and resentment). Misconception is the greatest sin, because it leads to the other sins; consequently, release from pain can only be achieved through knowledge and dispelling of ignorance. Knowledge comes from meditation, study and discussion, and internal discipline.
The Vaishesika school is believed to be the oldest of the six schools; the Vaishesika Sutras of Kanada were written just before teh Nyaya Sutras. The word vishesa means particularity, and this philosophy emphasizes the significance of the individual. The reality of the soul is inferred from the discernment that consciousness cannot be a property of the body, senses, or mind. Our actions effect our souls, which are individual and unique, even after liberation. Progress comes from virtue (dharma), but like the Nyaya school, liberation can only be achieved through knowledge: self-insight. When one realizes that all objects that seem either attractive or repulsive are merely compounds of atoms, their power over one ceases. True knowledge of the soul dispels self-interest in universal awareness. Each soul reaps the harvest of its deeds in this life or a future one, but with liberation it becomes absolutely free. The awareness of the seer is the vision of perfection which results from virtue.
The
Mimamsa school focuses on the
Vedas; in fact the word
Mimamsa means "interpretation," and the school originated as a school of Vedic interpretation. According to this school, the soul transcends the body, senses, and mind, being omnipresent, eternal, and many. Its salvation is dependent upon
dharma (like in the
Vaishesika school), but rather than external
virtue, here the focus is on
prayer,
ritual, and
sacrifice. It is this school which developed in detail the
law of karma.
Humans are
free and determine their own
destiny by their actions. The
karma from past actions does not limit free choices but is like capital that can be spent in various ways as it is resolved. The
soul usually carries a mixture of
good and evil consequences, and these may cancel each other. Obligations are actions which must be performed, or one gets demerit, though there is no merit for doing them. Prohibited actions if done also cause demerit, but if avoided likewise do not give merit. Optional actions may produce merit or demerit according to their consequences. The ultimate goal of practicing good
dharma is experiencing happiness in
heaven.
The Vedanta school, which originally developed from the Mimamsa school, eventually all but absorbed it. The Vedanta Sutra (also known as the Brahma Sutra was written by Badayarana, and is a terse work; however, many accesible commentaries were written on it in ancient times, the most popular ones being by Shankara and Ramanuja. The worde Vedanta means "end of the Vedas," referring to the Upanishads, the texts on which this school of philosophy focuses. Brahman is seen as the ultimate reality, complete, unchanging, and incomprehensible. All of existence and experience comes from Brahman, is dependent upon Brahman, and returns back into Brahman. The various paths of theistic devotion, sacrifice, virtuous work, etc., help to make an individual more receptive of the knowledge of Brahman, but the individual has to make the jump without any of these crutches, by destroying all attachment to everything external (this includes the Scriptures, philosphy, thinking, even a personal God!). There are two important interpretations of Vedanta doctrine:
- Shankara's interpretation is that all of what we sense as the "universe," including the individuality of our own souls, is maya, an illusion, false. When we realize Brahman we will wake up from this allusion, as if it were all a dream, and will be reunited with Brahman, our identity completely absorbed.
- Ramanuja's interpretation is that while Brahman is transcendent, it has internal diversity. That is, the perception of our individuality is not false, it is merely flawed because we cannot see the true, higher nature of everything in the form of Brahman. The universe does exist, but we are blind to Brahman and so are attached to meaningless things.
The
Sankhya school focuses on theoretical
knowledge. While acknowledging the holiness of the
Vedas, this school may have begun to develop independently of them.
Sankhya originated the idea of the three
gunas: the highest guna (
sattva or goodness, the middle guna (
rajas or passion) and the lowest guna (
tamas or darkness). It also originated the concept that the individual
soul (the
atman) was indestructable, unaffected by the external world.
Sankhya was originally an atheistic philosophy. Its evolution from a counterpart to
Yoga to a type of
Yoga itself can be seen in the
Bhagavadgita (See chapters 2 and 3). The role of counterpart to
Yoga was taken over by
Vedanta. It is said that
Buddha was taught
Sankhya.
The Yoga school focuses on achieving liberation through discipline. Yoga with a capital "Y" should not be confused with "yoga," which is simply any method of betterment (such as the physical exercises that are now popular (but for how long?) in the West). The Yoga school bases its practice on the doctrine of the Sankhya school; the goal was to quiet the inner turmoil in the individual so that it mirrors the true, transcendent, calm nature of the world, thus effecting liberation. Unlike the Sankhya school, Yoga includes a concept of God, but this God is not to be worshipped. Rather than devotionalistic, Yoga encourages seeing God as a model of detachment.
All six of these philosophies made its mark on history and Indian culture, but the
Vedanta philosophy moreso than others.
Vedanta was taught by
Ramakrishna and his disciple
Swami Vivekananda (who was immensely succesful in popularizing the doctrine in the West). It was also taught by
Swami Chinmayananda, whose
Vedanta-based
Chinmaya Mission centers still teach throghout the world (I went to one regularly as a kid). Among all of the philosphers mentioned in this writeup,
Shankara is by far the most popular and most widely read. (See his
Bhaja Govindam, a short introduction to the philosophy). The influence of
Vedanta is also seen in the
transcendentalists (Cf.
Ralph Waldo Emerson's poem
Brahma), and even in new-agers like
Deepak Chopra.