There are, broadly speaking, two traditions of semantics: the linguistic or conceptual tradition, which sees meaning as a cognitive phenomenon, and the logical or formal tradition, which sees meaning in terms of correspondences (truth-conditions) with an objective reality. This article adopts the linguistic or conceptual perspective. Many aspects of human cognition, such as basic perception, attention, and visual processing, are substantially shared with other primates. Language is primarily relevant to higher-order cognitive processes which are largely, if not entirely, species-unique. Importantly, human cognition not only includes reasoning and information processing about physical reality, it also includes so-called social cognition (Tomasello, 1999), that is, assessing and reasoning about intentions, mental states, and social situations, and it is in this arena that language has some of its clearest cognitive effects. (See Categorial Grammar and Formal Semantics; Social Cognition)