 For the Nyāya-Vaiśeṣika philosophers, pleasure and pain are not forms of cognition because they have different causes than cognitions [VS and VSU 10.1.5–6]. This means that we can have a cognition without a feeling and we can also have a feeling without a cognition. In addition, they are experienced differently [NM, vol. 1, p. 118]. This separation between cognitions and feelings, together with the view that feelings are defects that disturb cognitions, means that feelings are regarded as purely negative. They lead to an attachment to the world which causes a sense of self and this sense of self provides an obstacle to liberation.