The Nayay-Vaisesika Categories
Padartha Literally the "meaning or referent of a word." In the Nyaya-Vaisesika metaphysics the term "padartha" refers to the fundamental categories of reality that were first put forward in Kananda's Vaisesika Sutras but that were accepted by both the Nyayas and the Vaisesikas. Other Indian schools of thought put forward their own list of "padarthas".
Dravya "Substance". The most fundamental category according to the Nyaya-Vaisesikas. It is defined as the substrate of qualities and activities. The Nyaya-Vaisesikas recognized both eternal and non-eternal substances. Eternal substances they conceived to be without parts. The eternal substances are souls, atoms, space, time and ether (the substratum of sound). Non-eternal substances (also called "wholes" and "products") are composite substances that inhere in other substances and ultimately in atoms, e.g., a pot, the body of a cow.
Guna "Quality". According to the Nyaya-Vaisesikas a quality is an entity which has a substance for its substratum, has no further qualities, and is not the cause of, or concerned with, conjunction and disjunction (e.g. the red color of a rose, the cognition of a soul). Qualities in this system are property particulars (i.e. red is not redness, a universal that inheres in all "reds").
Karma In the Nyaya-Vaisesika category theory "karma" means motion. Motions inhere in substances and are the proximate and non-inherence causes of conjunctions and disjunctions. The Nyaya-Vaisesikas also, of course, affirmed the pan-Indic doctrine of karma according to which good deeds produce good fruit and bad deeds bad fruit. For them, though, we must posit God to explain this.
Samanya "Generality; class; universal feature". In the Nyaya-Vaisesika system "samanya" means universal. It is defined as a generic feature that resides in all members of a class (e.g. cowness, redness). Universals are one, eternal, and reside in many.
Samavya "Inherence". In the Nyaya-Vaisesika system, inherence is the universal glue that joins together qualities and motions with substances, wholes with their parts, universals with their particulars, and ultimate individuators with the things they individuate. Unlike conjunction (conceived by the Nyaya-Vaisesikas as a non-monadic quality), inherence is "inseparable" which means that things related by it cannot both exist in separation from each other. For example, a red color cannot continue to exist if it ceases to inhere in the substance it inheres in, and a cow cannot continue to exist if the universal cowness ceases to inhere in it, and neither a soul or the individuator inhering in it could continue to exist separate from each other!! In short, if two things related by inherence cease to be so related, at least one of them must be destroyed.
Visesa "Inviduator". In the Nyaya-Vaisesika system the visesas were posited in order two distinguish two eternal substances of the same specific kind from each other (e.g. two souls, or two earth atoms), there being no other way the distinction between them could be explained (or so the Nyaya-Vaisesikas thought).
Abhava "Non existence; absence, negation (from the verb root "bhu" = to be, exist, and "a" = not) The Nyaya-Vaisesikas recognized "absence" as a distinct category of "reality". Real absences always require and absentee, e.g. the absence of a pot on the ground, or of horns on the head of a man (thus there is no absence of sky flowers anywhere since sky flowers don't exist). The "absentee" is also called the "counter-positive". There are four basic kinds of absence, prior absence, posterior absence, absolute absence, and mutual absence. Before a thing exists there is its prior absence; after it ceases to exist there is its posterior absence. There is an absolute absence of color in air. There is mutual absence between a pot and a cloth (i.e. there is an absence of identity between them). The later Nyaya recognized even more kinds of absences and their theory of absence became incredibly sophisticated and complex.