  Logic is developed in classical India within the traditions of epistemology. Inference is a second knowledge source, a means whereby we can know things not immediately evident through perception. Oetke (2004) finds three roots to the earliest concerns with logic in India: (1) common-sense inference, (2) establishment of doctrines in the frame of scientific treatises (śāstra), and (3) justification of tenets in a debate. The three of these come together (though the latter two are predominant) within the epistemological traditions in an almost universal regard of inference as a knowledge source.