Every sentence conveys a temporal point of view through its aspectual meaning. This viewpoint arises through presenting a situation from a certain temporal perspective and indirectly classifying the situation as an exemplar of an idealized situation type. The information is conveyed by the aspectual categories of a language. This paper presents a general approach to aspect in which situation type and viewpoint are posited as the two components of aspectual meaning. The components are independent and interact systematically in sentences to give aspectual information. Arguments are presented for the independence of the components, including a discussion of the relation between statives and progressives. Then, the paper considers issues concerning situation types and argues for two levels of classification, basic and derived. The paper concludes with a bounding paradox suggesting that independently bounded events have unique properties that should be recognized in the grammar of a number of languages. It is suggested that contrastive meaning is an important element in understanding the force of apsectual choice, and that this information is part of the pragmatic knowledge that speakers have of their language. (Contains 18 references.) (CK)