Nyāya understands error (bhrama, mithyā-jñāna) as a cognition that misrepresents its object, a knowing that does not correspond to the way things actually are. A traditional formulation is that it is the cognition of an object “as something other than what it is,” such as taking a rope to be a snake or seeing silver in what is in fact a shell. In such cases, there is a definite judgment, not mere hesitation: the mind settles on “this is a snake” or “this is silver,” even though the object before it is otherwise. Error, then, is not an absence of knowledge but a positive, determinate cognition whose content fails to match reality.

To account for how this happens, Nyāya advances the theory of anyathākhyāti, often rendered as the “misapprehension as something otherwise.” In an erroneous perception, there is a real substratum—such as the shell or the rope—actually present before the senses. Alongside this, there is the memory of another real object—silver seen elsewhere, or a snake known from past experience—which, due to similarity and defective conditions, becomes superimposed upon the present perception. The error lies in attributing this remembered, real entity to the wrong locus, so that what is truly here and now is taken to be something that is not here and now.

Nyāya emphasizes that such false cognitions are conditioned by defects (doṣa) in the cognitive process. These defects may involve the sense organs, the contact between sense and object, the surrounding conditions such as dim light or distance, or the internal operations of memory and attention. When these factors are impaired, the ordinarily reliable means of knowledge (pramāṇa) give rise not to valid cognition (pramā) but to error. Yet even in error, the elements involved—the substratum and the remembered object—are themselves real; what fails is the proper coordination of them in cognition.

The path out of such confusion is the arising of a later, non-defective cognition that discloses the object as it truly is, for example, “this is a shell” or “this is a rope.” Practical engagement with the object—such as attempting to grasp the supposed silver and finding only a shell—also reveals the earlier misjudgment. Nyāya thus treats the analysis of error as spiritually and philosophically significant: by carefully discerning how and why the mind mistakes one thing for another, the seeker learns to distinguish reliable insight from misleading appearance, and to rely increasingly on cognitions that stand the test of reality and action.