 Gautama provides a definition at Nyāya-sūtra 1.1.7: “Testimony is the (true) statement of an expert (āpta).” An “expert,” āpta, is a trustworthy authority such that “expert” is not entirely adequate as a translation. Vātsyāyana in defining the term outlines a moral dimension. An āpta is a person who not only knows the truth but who wants to communicate it without deception (Vātsyāyana’s commentary under Nyāya-sūtra 1.1.7). The commentator also brings out a certain egalitarianism in the workings of the knowledge source. Contra the privilege afforded the priestly caste in matters of Vedic interpretation, he says that even foreigners—“barbarians,” mleccha—can be the experts whose statements convey to us testimonial knowledge, provided, as always, they know the truth and want to communicate without deception.