the mind which perceives cognitions].[197] Hence we conclude that the fourth or remaining opinion must be the true one, viz., that darkness is only the absence of light. And it need not be objected that it is very difficult to account for the attribution to non-existence of the qualities of existence, for we all see that the quality happiness _is_ attributed to the absence of pain, and the idea of separation is connected with the absence of conjunction. And you need not assert that "this absence of light must be the object of a cognition produced by the eye in dependence on light, since it is the absence of an object possessing colour,[198] as we see in the case of a jar's absence," because by the very rule on which you rely, viz., that that on which the eye depends to perceive an object, it must also depend on to perceive that object's absence, it follows that as there is no dependence of the eye on light to perceive light, it need not depend thereon to perceive this light's absence. Nor need our opponent retort that "the cognition of darkness [as the absence of light] necessitates the cognition of the place where the absence resides [and _this_ will require light]," as such an assertion is quite untenable, for we cannot admit that in order to have a conception of absence it is necessary to have a conception of the place where the absence resides, else we could not have the perception of the cessation of sound, as is implied in such an expression as "the tumult has ceased."[199] Hence, having all these difficulties in his mind, the venerable Kaṇáda uttered his aphorism [as an _ipse dixit_ to settle the question]: "_Dravya-guṇa-karma-nish-patti-vaidharmyád abhávas tamas_" (_Vaiś. Sút._ v. 2, 19), "Darkness is really non-existence, since it is dissimilar to the production of substances, qualities, or actions." The same thing has been also established by the argument that darkness is perceived by the eye[200] [without light, whereas all substances, if perceptible at all, require the presence of light as well as of the eye to be visible]. Non-existence (_abháva_) is considered to be the seventh category, as established by negative proofs. It may be concisely defined as that which, itself not having intimate relation, is _not_ intimate relation;[201] and this is twofold, "relative non-existence"[202] and "reciprocal non-existence." The former is again divided into "antecedent," "emergent," and "absolute." "Antecedent" is that non-existence which, though without any beginning, is not everlasting; "emergent" is that which, though having a beginning, is everlasting; "absolute" is that non-existence which abides in its own counter-entity;[203] "reciprocal non-existence" is that which, being different from "absolute," has yet no defined limit [_i.e._, no _terminus ad quem_ nor _terminus a quo_, as "antecedent" and "emergent" have].