 The important aspect of the Nyāya-Vaiśeṣika account is that the individual emotions, such as attachment and aversion are regarded as defects (doṣas) [NB 1.1.18] or impurities (upadhā) [VS and VSU 6.2.4]. These defects are the result of ignorance (mithyājñāna) and they give rise to actions that lead to the feeling of pleasure or pain. The reason why this is regarded as negative is that the feeling of pleasure and pain is responsible for our attachment to the world and, more importantly, for our attachment to the self and therefore presents an obstacle to liberation. For this reason, any emotion is deemed to have a negative influence on the individual. However, NV 1.1.22 mentions one exception, namely the desire for eternal pleasure and absence from pain which is final liberation. While, strictly speaking, a desire is not an emotion, it usually has the same negative effect because it results in attachment to the object of desire. The desire for eternal pleasure, however, is not detrimental to liberation; in fact it is a precondition for liberation.