Underlying premises in dravya gunam

1. Only substance is the material cause of action.
2. There are 9 categories of substance, according to Vaishshika: space, air, fire, water, earth (elements), soul, mind, time, and direction.
3. These 9 causative substances are studied through 7 categories (padartha): dravya (substance), guna (attribute), karma (action), samanya (commonality), vishesha (uniqueness), samavaya (inherence), abhhava (non-existence).
4. All substances are composed of the 5 elements (space, air, fire, water, earth)
5. In a system which brings together substances of similar quality (guna) that quality increases in that system. Similarity is always the cause of increase and builds homogeneity and unity (called Samanya Siddhanta).
6. Conversely, if in a given system substances of opposite qualities come together there is a decrease in the expression of those qualities. Dissimilarity is always the cause of decrease and builds heterogeneity and diversity9 (called Vishehsa Siddhanta).
7. Like attracts like—similar qualities attracting is the basis of affinity, attraction, selectivity. This principle is the basis of drugs working predominantly in a given tissue, organ, system, etc.