The logical debate in India of the first millennia AD revolved around the concept of
. The term
was taken to mean ’the criterion of knowledge’. Current researchers of Indian philosophy are certain that Indian logicians all agreed that
is the sound operation of the mental processes which produce mental knowledge episodes. Conversely, according to my research, Nyāya thinkers believed the criteria of knowledge are the rules of the use of things in everyday habitual behaviors. The issue which stood at the center of the Indian logical debate, I wish to suggest, was the following: On the one hand, there were thinkers who believed the rules of logic were prior to and independent of habitual everyday human behaviors. On the other hand, there were the Naiyāyikas who believed the rules of logic were derived from habitual everyday human behaviors and the rules of usage they provided.