Padartha in Hindu philosophy literally means the meaning of a word. A padartha is an object which can be thought (artha) and named (pada). Everything which exists and everything which is experienced, whether in the external world or in the mind, is padartha.
The concept of padartha or category is the most significant philosophy put forth by the Vaisesika School of Indian philosophy. The categories (padartha) attempt a complete analysis of the objects of knowledge.
For Prasastapada, the padarthas are the most comprehensive units of enumeration, the ultimate divisions of reality, and the most basic correlate of thought and speech. The classical version of this list of categories is found in Padartha Dharma-Sangraha of Prasastapada. They are dravya (substance), guna (quality), karma (action), samanya (generality), visesa (particularity), samavaya (inherence) and abhava (non-being).
Abhava (non-being) does not appear in the list of Prasastapada and Kanada. It was added by the latter Vaisesikas – Sridhara, Udayana and Sivaditya.
The first three categories of substance, quality and action possess a real objective existence. Kanada calls them artha and declares that we can have an intuition of them. The other three – generality, particularity and inherence – are products of intellectual discrimination (buddyapeksham). They are logical categories and not capable of direct apprehension.
In early Vaisesika, while all the categories are said to possess the feature of existence in general (astitva), a distinction is made between two kinds of being (astitva) : sattasam-bandha, ascribed to qualities, substance, and action; and svatma sattva, or the being of generality, particularity and inherence. Svatma Sattva (self-sufficient existence) is independent of space and time, and therefore something which belongs to the timeless category.