From the stand point of the Indian philosophy, we may say that there is one or more ultimate realities in the universe. By the term ultimate reality, we generally mean something that exists by itself, without depending on any other thing. All philosophical systems of India have admitted the existence of at least one Ultimate Reality. Thus Advaita Vedānta has Nirguna Brahman; Nyaya – Vaiseshika have single God and eternal atoms; Samkhya propose two ultimate realities, Purusha and Prakriti. The Hinayana Buddhists believe in the reality of multiple momentary entities. The Mahayanist’s theories in Prajna and Vijnaptimatra are akin to the belief in an ultimate reality.
A classification of Indian philosophical systems based on their concept about the ultimate reality (or realities) is possible and it will be helpful to understand the comings articles or chapters.
Carvākās or Lokāyata considers Matter as the only ultimate reality. Perception is the sole Pramāna (means of knowledge). Earth, water, air and fire are the four primary elements. Consciousness is the product of these material elements, when they combine in certain proportion, just like intoxication is produced by mixing a number of ingredients which by themselves are not intoxicants.
There is a split among the Cārvākas regarding ‘what is the soul?’ Some believe that human body itself is the Soul. Others opine that mind is the soul; senses are the soul; Prana is the soul, etc. Soul is not an eternal thing, but it perishes when human body perish, Cārvākas says.
Cārvākas do not believe in afterlife. Death itself is the emancipation. So live happily here. Enjoy maximum. No built-in ethics in Cārvāka Systems. But that does not mean that followers of this system are anarchists or law breakers. Rather Cārvākas held that each person can maintain his own ethics. They may also have been accepted the cause – effect relation, but it limit to this world only.
Dualists say that there are ultimately two irreducibly ultimate realities. In Indian philosophy, Samkhya system is dualistic. It posits two Ultimate realities – Prakriti and Purusha. Each one can’t reduce to the other. Here Prakriti is by default a dead substance, but association with Purusha give ‘life’ to it and it starts to evolve then for the Purusha. Details will be touched upon another post.
Realist philosophical schools say that external world has independent existence apart from the mind of the seer (one who sees). Perceived objects have independent existence from the perceiver. Suppose a seer views a tree. Then seer and tree, both are real. Existence of the tree does not depend upon the seer. If the seer dies, tree will remain the same in nature. To have a mental impression of a tree in the seer’s mind, a tree existing outside of the seer’s body is must. This is the position of the realist.
In Indian philosophy Samkhya, Yoga, Nyaya, Vaiseshika, Purva mimamsa, Vaibhasika, Sautrantika, and Jains are the popular realist schools.
In idealism, mind is the only reality. Existence of external world depends upon the seer’s mind. When we see a tree, as per idealism, it is a projection of mind. External tree is rooted in our thought. External world is nothing, but a stream of such thoughts or consciousnesses coming to mind continuously. Avidya is the main reason for the continuous stream of consciousness.
Buddhist Vijnanavada sect is an Absolute Idealistic school of Indian Philosophy. Roughly Advaita Vedānta school also falls in this category, though spiritual idealism is also given to it elsewhere. In strict sense, Buddhist Vijnānavāda sect is pure idealists in Indian Philosophy.
Pluralist schools approve the existence of multiple eternal realities. Vaiseshika, Nyāya, Jaina, etc are the advocates of pluralism in Indian Philosophy. They states that there are innumerable atoms, which combine in certain proportions to form the aggregates. Thus they are atomists too. They say multiple souls exist, which are also eternal like god. These multiple souls may be qualitatively same or not.
Vaiseshika school is the first advocates of Atomism in the world philosophy. Atomism in Indian Philosophy doesn’t start with Rishi Kanada. Most recognized theory is Kanada assembled the then prevalent Atomic theories and arranged & synthesised them into a single and rigid frame work.
This group believes that everything happening in this world is already fixed or determined by fate. Future and after-life of human beings is also fixed. We only live according to the decree of fate. Human efforts are useless. Efforts cannot change/alter/influence our future life. Ethics do not need to practice as it can’t influence future.
The only fatalist sect of Indian Philosophy is Ājīvika. Much information is not available about them. They are supposed to much linked with Jainism. Their leader Makkali Gosala is considered as the contempory of Sri Buddha and Mahavira.
Nihilists asserts that ‘Nothing exists’. External world exists in so many relations (dependency) and each relation depends on further relations. This bunch of relations finally leads to full contradictions questioning the existence of every being.
The only nihilistic school of Indian Philosophy is Buddhist Sathyasiddhi school. They are known as Sarva sunyavadins as per the available sources. Harivarman, who lived before Vasubandhu, is considered as the founder of this sect. Instead of telling that ‘everything is void’, this school says ‘even void do not exist’.
There is a popular belief that Nagarjuna’s madhyamaka system (Sunyavada) is nihilistic. It is an utterly foolish claim. Nagarjuna’s usage of word ‘sunya’ does not mean ‘voidness’. Its meaning can be taken as ‘relative’ or ‘indescribable’. Nagarjuna clearly admits an ultimate reality and call it as ‘Prajna’ which is above the momentary phenomenal plane. Prajnaparamita Literature clearly establish this truth.
Thus Indian Philosophy contains many schools of various thought streams. Such diverse opinions about the existence of reality and the co-existence of all of them for a long time can point to the rich cultural and philosophic calibre of Indians and the liberal atmosphere and mutual respect, under which the various philosophical schools developed their theories and flourished, that ancient Indians cultivated among them.
 Though both of the terms usually denote the materialist school, there can be certain differences between them. Extreme meager evidences are available about materialist school of Indian philosophy. But in almost all major philosophical works, materialism finds its place, giving the hint that it had adherents at all time in India.
 As per popular opinion, Vijnānavāda advocates subjective idealism. But it is false. Vasubandhu clearly posits an ultimate reality which is unchanging and eternal. He calls it as Vijnāptimātra.
 Read ‘Indian Idealism’ by SN Dasgupta.
 Read “The Ājīvikas” by Beni Madhav Barua and ‘History and doctrines of the Ājīvikas’ by A L Basham.
 There is almost no literature in India which lists this sect’s philosophy and practice. But Junjiro Takakusu brings some light into their doctrine by citing a Chinese document. Read his ‘The Essentials of Buddhist Philosophy’.