Categories

2. Three important systems of categories: Vaiśeṣika

A second early system of categories can be found in the Vaiśeṣikasūtra (second–third century AD), a text that provides the foundation for one of the most influential ontological systems in the Indian philosophical tradition (see Ontology in Indian philosophy). It distinguishes six categories: substances, qualities, motion, universals, individuators, and inherence. (A seventh category, nonexistence, was later added to the system.) Each of these is then variously subdivided; the category of substance, for example, is comprised of nine subcategories, earth, water, fire, wind, ether, time, selves, and the mind. The qualities are particularized properties of the substances and depend on them for their existence. As such the qualities cannot be shared between substances and could not exist without the substances in which they inhere. The various forms of motion describe what the substances do, allowing the explanation of microscopic and macroscopic processes. Unlike qualities, universals are repeatable and eternal; they can be shared by more than one instantiator and do not cease to exist when the instantiator does. Individuators act as unique identifiers of individual eternal, noncomposite substances, such as atoms or selves. The Vaiśeṣika categories are held together by inherence, a cross-category relation. Universals inhere in qualities, which in turn inhere in substances. Compound substances inhere in their parts, and atomic substances have individuators inhering in them.

The Vaiśeṣika system has an interesting take on the epistemology of ontological categories. It assumes that a specific form of perception that is the result of processes of mind-training (yogipratyakṣa) allows us to obtain direct knowledge of the world at the categorial level (Isaacson 1993; see also Sense perception, Indian views of). In particular, the trained practitioner is taken to be able to observe the particularities of individual atoms (some of the categorial structure of the world is said to be accessible to the ordinary observer, but its entirety can only be perceived by the meditatively trained). This approach avoids the necessity of an epistemological detour via an analysis of language or concepts in order to extract some system of categories from them. Such a route may still be taken, but it is dispensable. Knowledge of the categories can be gained by relying on the authority of experts that have refined their perceptual capacities in such a way that they can directly perceive the underlying structure of reality.