In Nyāya thought, perception (pratyakṣa) is regarded as the primary and most fundamental means of valid knowledge. It is defined as non-erroneous, direct cognition that arises from the contact (sannikarṣa) between a sense organ and its proper object, without dependence on inference or verbal testimony. This contact must be immediate rather than mediated, and the resulting awareness is taken to correspond faithfully to a real object, thereby excluding illusion and hallucination from the category of genuine perception. For perception to occur, there is a coordinated involvement of self (ātman), mind (manas), the relevant sense organ (indriya), and the object (artha), all participating in a single cognitive event.

Nyāya further distinguishes between external and internal perception. External perception (bāhya pratyakṣa) arises through the five senses—sight, hearing, smell, taste, and touch—when they come into proper relation with external objects. Internal perception (mānasa pratyakṣa) concerns awareness of inner states such as pleasure, pain, desire, and similar mental conditions, apprehended through the mind’s contact with the self. In both cases, perception remains direct and immediate, though the “field” of awareness shifts from outer objects to inner experiences.

A subtle analysis of the structure of awareness leads Nyāya to speak of two stages or modes of perception. The first, nirvikalpaka (indeterminate) perception, is a pre-conceptual awareness that does not yet sort the object into named categories or explicit relations—there is a simple, bare “presence” of something. The second, savikalpaka (determinate) perception, is conceptually articulated: the object is grasped along with its qualifiers and relations, as in the cognition “this is a blue pot.” Here universals, particularity, qualities, and relations are synthesized into a single, structured judgment.

Nyāya also recognizes a distinction between ordinary and extraordinary perception. Ordinary (laukika) perception covers the usual sensory and mental cognitions just described. Extraordinary (alaukika) perception refers to less common modes of awareness, including the perception of universals (sāmānyalakṣaṇa), perception shaped by prior knowledge or impressions (jñānalakṣaṇa), and yogic perception (yogaja) attributed to advanced practitioners. Even in these extraordinary cases, the tradition maintains the same logical ideal: perception is a direct, non-erroneous disclosure of what truly is, and thus stands as a privileged gateway to truth.