  Briefly we may consider the more exotic candidate sources proposed in the classical literature mainly within Mīmāṃsā (often elaborated by Vedāntins), beginning with analogy, which is viewed as the pramāṇa for knowledge of similarity in Mīmāṃsā and Vedānta but is rejected by the other schools, Vedic and non-Vedic alike, except for Nyāya which however provides a radical reinterpretation. To provide a hermeneutics of Vedic injunctions to make them suitable for practice in actual performances, the Mīmāṃsā exegetes need to be able to designate substitutes, of one type of grain for another, for example, or one animal for another, depending upon availability in the first place but upon similarity in the second place. In Vedānta, analogy is useful for understanding the Upanishads which make comparisons between spiritual or yogic experience and the experiences of ordinary humans, as pointed out by Kumar (1980: 110). Yogācāra, Jaina, and Nyāya logicians find similarity—or relevant similarity—to figure in inference as a knowledge-generating process. It is through cognizing similarity and dissimilarity that we arrive at knowledge of pervasion as required for inferential knowledge. A kitchen hearth counts as an “example” in the stock inference because of its relevant similarity to the mountain which is the center of inquiry. It is part of what is called the sapakṣa, the set of positive correlations, that make us know an inference-underpinning pervasion. Knowledge of similarity is not viewed in Nyāya (or Yogācāra, etc.) as the result of analogy as a knowledge source—for Nyāya, analogy is restricted to a subject’s learning the meaning of a word (and Yogācāra does not countenance it as a separate pramāṇa). But pervasion is known typically through generalization from cases (although in some cases a single observation, some say, will suffice), presupposing knowledge of relevant similarity which can be a matter of perception.