The principle that final bliss, _i.e._, the absolute abolition of pain, arises from the knowledge of the truth [though in a certain sense universally accepted], is established in a special sense as a particular tenet[205] of the Nyáya school, as is declared by the author of the aphorisms in the words "proof, that which is to be proved, &c.,--from knowledge of the truth as to these things there is the attainment of final bliss." This is the first aphorism of the Nyáya Śástra. Now the Nyáya Śástra consists of five books, and each book contains two "daily portions." In the first daily portion of the first book the venerable Gotama discusses the definitions of nine categories, beginning with "proof," and in the second those of the remaining seven, beginning with "discussion" (_váda_). In the first daily portion of the second book he examines "doubt," discusses the four kinds of "proof," and refutes the suggested objections to their being instruments of right knowledge; and in the second he shows that "presumption," &c., are really included in the four kinds of "proof" already given [and therefore need not be added by the Mímáṃsakas as separate ones]. In the first daily portion of the third book he examines the soul, the body, the senses, and their objects; in the second, "understanding" (_buddhi_), and "mind" (_manas_). In the first daily portion of the fourth book he examines "volition" (_pravṛitti_), the "faults," "transmigration," "fruit" [of actions], "pain," and "final liberation;" in the second he investigates the truth[206] as to the causes of the "faults," and also "wholes" and "parts." In the first daily portion of the fifth book he discusses the various kinds of futility (_játi_), and in the second the various kinds of "occasion for rebuke" (_nigrahasthána_, or "unfitness to be argued with"). In accordance with the principle that "to know the thing to be measured you must first know the measure," "proof" (_pramáṇa_) is first enunciated, and as this must be done by defining it, we have first a definition of "proof." "Proof" is that which is always accompanied by right knowledge, and is at the same time not disjoined from the proper instruments [as the eye, &c.], and from the site of knowledge [_i.e._, the soul];[207] and this definition thus includes the peculiar tenet of the Nyáya School that God is a source of right knowledge,[208] as the author of the aphorisms has expressly declared (ii. 68), "and the fact of the Veda's being a cause of right knowledge, like spells and the medical science, follows from the fact that the fit one who gave the Veda was a source of right knowledge." And thus too hath the universally renowned teacher Udayana, who saw to the farthest shore of the ocean of logic, declared in the fourth chapter of the Kusumáñjali: "Right knowledge is accurate comprehension, and right knowing is the possession thereof; authoritativeness is, according to Gotama's school, the being separated from all absence thereof.