Nyāya Sūtras 10

What, again, is the multitude of objects to be validly cognized by this means of valid cognition?

But the self, body, sense organs, objects of the sense organs, cognition, mind, activity, defect, rebirth, fruition, pain, and release are the object of valid cognition.

There, the self is the seer of all, the experiencer of all, omniscient, the perceiver of all. Its locus of experience is the body. The instruments of experience are the sense organs. The things to be experienced are the objects of the sense organs. Experience is cognition. Since the sense organs are not capable of apprehending all objects, the internal organ whose domain is all objects is the mind. Activity is the cause of the continuation of the body, sense organs, objects of sense organs, cognition, and feelings of pleasure; and so are defects. This body of his is not without a preceding one, nor is it without a succeeding one; of previous bodies there is no beginning, and release is the end of succeeding ones: this is rebirth. Fruition is the experience of pleasure and pain along with their means. As for pain, this is not a denial of the awareness of pleasure that is felt as agreeable. What then? This instruction on the cultivation of meditative concentration is given because birth itself, along with the means to pleasure, is pain, owing to the connection with pain, non-separation from pain, and association with various kinds of affliction.

— because of its association with pain, because it is inseparable from pain, it is taught [as pain]. One who is collected meditates; meditating, he becomes disenchanted; for the disenchanted there is detachment; for the detached there is liberation. Liberation is the severing of the continuous series of birth and death, the abandoning of all pain. There are also other objects of valid cognition, such as substance, quality, action, universal, particularity, and inherence, and by their subdivisions they are innumerable; but it is through knowledge of reality regarding this [set of objects of valid cognition] that liberation occurs, and from false knowledge that saṃsāra continues; therefore this is specifically taught.