Vaisheshika or Vai?e?ika (Sanskrit: ?) is one of the six orthodox schools of Hindu philosophy (Vedic systems) from ancient India. In its early stages, the Vai?e?ika was an independent philosophy with its own metaphysics, epistemology, logic, ethics, and soteriology. Over time, the Vai?e?ika system became similar in its philosophical procedures, ethical conclusions and soteriology to the Ny?ya school of Hinduism, but retained its difference in epistemology and metaphysics.
The epistemology of Vai?e?ika school of Hinduism, like Buddhism, accepted only two reliable means to knowledge: perception and inference. Vai?e?ika school and Buddhism both consider their respective scriptures as indisputable and valid means to knowledge, the difference being that the scriptures held to be a valid and reliable source by Vai?e?ikas were the Vedas.
Vaisheshika school is known for its insights in naturalism, it is a form of atomism in natural philosophy. It postulated that all objects in the physical universe are reducible to paramu (atoms), and one's experiences are derived from the interplay of substance (a function of atoms, their number and their spatial arrangements), quality, activity, commonness, particularity and inherence. According to Vai?e?ika school, knowledge and liberation were achievable by complete understanding of the world of experience.
Although the Vaisheshika system developed independently from the Nyaya school of Hinduism, the two became similar and are often studied together. In its classical form, however, the Vaishesika school differed from the Nyaya in one crucial respect: where Nyaya accepted four sources of valid knowledge, the Vaishesika accepted only two.
Vaisheshika espouses a form of atomism, that the reality is composed of four substances (earth, water, air, fire). Each of these four are of two types, explains Ganeri, atomic (paramu) and composite. An atom is that which is indestructible (anitya), indivisible, and has a special kind of dimension, called "small" (a?u). A composite is that which is divisible into atoms. Whatever human beings perceive is composite, and even the smallest perceptible thing, namely, a fleck of dust, has parts, which are therefore invisible. The Vai?e?ikas visualized the smallest composite thing as a "triad" (trya?uka) with three parts, each part with a "dyad" (dya?uka). Vai?e?ikas believed that a dyad has two parts, each of which is an atom. Size, form, truths and everything that human beings experience as a whole is a function of atoms, their number and their spatial arrangements.
Vaisheshika postulated that what one experiences is derived from dravya (substance: a function of atoms, their number and their spatial arrangements), guna (quality), karma (activity), samanya (commonness), vishesha (particularity) and samavaya (inherence, inseparable connectedness of everything).
Hinduism identifies six Pramas as epistemically reliable means to accurate knowledge and to truths:Pratyak?a (perception), Anum?na (inference), Upam?na (comparison and analogy), Arth?patti (postulation, derivation from circumstances), Anupalabdhi (non-perception, negative/cognitive proof) and ?abda (word, testimony of past or present reliable experts). Of these Vai?e?ika epistemology considered only pratyak?a (perception) and anum?na (inference) as reliable means of valid knowledge. Nyaya school, related to Vai?e?ika, accepts four out of these six.
The earliest systematic exposition of the Vaisheshika is found in the Vai?e?ika S?tra of Kada (or Ka?abhaksha). This treatise is divided into ten books. The two commentaries on the Vai?e?ika S?tra, R?va?abhya and Bh?radv?jav?tti are no more extant. Pra?astap?da's Pad?rthadharmasa?graha (c. 4th century) is the next important work of this school. Though commonly known as bhya of Vai?e?ika S?tra, this treatise is basically an independent work on the subject. The next Vaisheshika treatise, Candra's Da?apad?rthastra (648) based on Pra?astap?da's treatise is available only in Chinese translation. The earliest commentary available on Pra?astap?da's treatise is Vyoma?iva's Vyomavat? (8th century). The other three commentaries are ?ridhara's Ny?yakandal? (991), Udayana's Kiran?vali (10th century) and ?rivatsa's L?l?vat? (11th century). ?iv?ditya's Saptapad?rth? which also belongs to the same period, presents the Ny?ya and the Vai?e?ika principles as a part of one whole. ?a?kara Mi?ra's Upask?ra on Vai?e?ika S?tra is also an important work.
According to the Vaisheshika school, all things that exist, that can be cognized and named are pad?rthas (literal meaning: the meaning of a word), the objects of experience. All objects of experience can be classified into six categories, dravya (substance), gu?a (quality), karma (activity), s?m?nya (generality), vi?e?a (particularity) and samav?ya (inherence). Later Vai?e?ikas (?r?dhara and Udayana and ?iv?ditya) added one more category abhava (non-existence). The first three categories are defined as artha (which can perceived) and they have real objective existence. The last three categories are defined as budhyapek?am (product of intellectual discrimination) and they are logical categories.
1.Dravya (substance): The substances are conceived as 9 in number. They are, p?thv? (earth), ap (water), tejas (fire), v?yu (air), ?ka?a (ether), k?la (time), dik (space), ?tman (self or soul) and manas (mind). The first five are called bh?tas, the substances having some specific qualities so that they could be perceived by one or the other external senses.
2.Gu?a (quality): The Vai?e?ika S?tra mentions 17 gu?as (qualities), to which Pra?astap?da added another 7. While a substance is capable of existing independently by itself, a gu?a(quality) cannot exist so. The original 17 gu?as (qualities) are, r?pa (colour), rasa (taste), gandha (smell), spar?a (touch), sa?khy? (number), parima (size/dimension/quantity), p?thaktva (individuality), sa?yoga (conjunction/accompaniments), vibh?ga (disjunction), paratva (priority), aparatva (posteriority), buddhi (knowledge), sukha (pleasure), du?kha (pain), icch? (desire), dve?a (aversion) and prayatna (effort). To these Pra?astap?da added gurutva (heaviness), dravatva (fluidity), sneha (viscosity), dharma (merit), adharma (demerit), ?abda (sound) and sa?sk?ra (faculty).
3.Karma (activity): The karmas (activities) like gu?as (qualities) have no separate existence, they belong to the substances. But while a quality is a permanent feature of a substance, an activity is a transient one. ?ka (ether), k?la (time), dik (space) and ?tman (self), though substances, are devoid of karma (activity).
4.S?m?nya (generality): Since there are plurality of substances, there will be relations among them. When a property is found common to many substances, it is called s?m?nya.
5.Vi?e?a (particularity): By means of vi?e?a, we are able to perceive substances as different from one another. As the ultimate atoms are innumerable so are the vi?e?as.
6.Samav?ya (inherence): Kada defined samav?ya as the relation between the cause and the effect. Pra?astap?da defined it as the relationship existing between the substances that are inseparable, standing to one another in the relation of the container and the contained. The relation of samav?ya is not perceivable but only inferable from the inseparable connection of the substances.
According to the Vai?e?ika school, the trasare?u are the smallest mahat (perceivable) particles and defined as trya?ukas (triads). These are made of three parts, each of which are defined as dvya?uka (dyad). The dvya?ukas are conceived as made of two parts, each of which are defined as paramu (atom). The paramus (atoms) are indivisible and eternal, they can neither be created nor destroyed. Each paramu (atom) possesses its own distinct vi?e?a (individuality).
The measure of the partless atoms is known as parimaala parima. It is eternal and it cannot generate the measure of any other substance. Its measure is its own absolutely.