Anyathakyativada of Nyaya:
The Nyaya theory of error is similar to that of Kumarila's Viparita-khyati. The Nyayayikas also believe like Kumarila that error is due to a wrong synthesis of the presented and the represented objects. The represented object is confused with the presented one. The word 'anyatha' means 'elsewise' and 'elsewhere' and both these meanings are brought out in error. The presented object is perceived elsewise and the represented object exists elsewhere. The shell and the silver are both separately real; only their synthesis, their relation as 'shell-silver', is unreal. Nayyayika maintains that the revival of 'silver' in memory is due to a 'complicated perception' [jnanalakshnapratyaksha] which is a variety of aloukika pratyaksha. Thus Nayyayika wants to make the represented silver as actually perceived, though in an extraordinary way. He further maintains that the knowledge is not intrinsically valid but becomes so on account of extraneous conditions. If correspondence theory does not apply, the successful activity as the test of the truth should be accepted as the criterion of truth. Kumarila holds non-contradiction to be the nature of truth and regards all knowledge as intrinsically valid.