Nyāya, with its rigorous concern for logic and valid knowledge, has often been challenged for what many see as an overemphasis on discursive reasoning. Critics from traditions such as Advaita Vedānta and various Buddhist schools argue that ultimate truth cannot be fully captured by syllogisms, definitions, and classifications, however refined. From this perspective, Nyāya’s intricate logical machinery is valuable for debate and clarification, yet remains inadequate as a vehicle for direct, non-conceptual realization. The heavy reliance on pramāṇas, especially perception and inference, is also questioned: some point to circularities in justifying inference, and to the difficulty of cleanly distinguishing valid from invalid inferences in subtle cases. This concern extends to Nyāya’s detailed work on language, doubt, and fallacies, which some see as risking entanglement in conceptual proliferation rather than release from it.

Metaphysically, Nyāya’s robust realism and atomism attract sustained criticism. The school’s commitment to external objects existing independently of consciousness is challenged by Buddhist idealists and some Vedāntins, who maintain that what is known is always shaped by consciousness and mental construction. The atomic theory, while offering a clear structure for physical reality, is said to struggle with explaining the unity of conscious experience and the relation between eternal atoms and transient compounds. Nyāya’s complex ontology of categories—substances, qualities, actions, universals, inherence, absence, and so on—is sometimes viewed as multiplying entities beyond necessity, with notions like inherence and absence appearing especially obscure or ad hoc to opponents.

Nyāya’s understanding of self and liberation also becomes a focal point of critique. The doctrine of countless distinct, eternal selves is rejected by Buddhists, who deny any enduring ātman, and is seen by Advaita thinkers as contradicting the nondual nature of reality. Furthermore, the Nyāya conception of mokṣa as the mere cessation of suffering, without a strongly articulated positive content, is regarded by some as limited or spiritually unsatisfying when compared to traditions that emphasize a more explicitly blissful or unitary realization. This is linked to the charge that Nyāya’s path leans too heavily on correct cognition and argumentation, giving comparatively less attention to transformative practices, devotion, or deep insight into impermanence and non-self.

The theological dimension of later Nyāya invites additional objections. Its elaborate logical proofs for a creator God (Īśvara) are criticized by Mīmāṃsā and Buddhist thinkers as either unnecessary or philosophically weak, particularly where they rely on causal reasoning from the existence of the world to a divine arranger. Questions are raised about how such a deity relates to individual karma and freedom, and whether positing Īśvara genuinely clarifies the structure of reality or simply adds another contested entity. Across these lines of critique—epistemological, metaphysical, soteriological, and theological—Nyāya is thus portrayed by its opponents as a powerful but ultimately limited framework, illuminating many aspects of thought and debate while, in their view, falling short of the deepest spiritual insight.