This course is an introduction to a scientific approach to meaning. Just like any scientist, a semanticist doesn't pursue the object of inquiry (i.e. meaning) directly, but rather focuses on related phenomena. We will focus on composition: the idea that the meaning of a whole (e.g. "spotted butterfly") is composite of the meanings of its parts (e.g. the meaning of "spotted" and the meaning of "butterfly"). We also focus on truth: the idea that we understand the meaning of a sentence by understanding what the world would have to be like for the sentence in question to be true (e.g. you understand the meaning of "It is raining in Seattle" because you know what the world would have to be like for that sentence to be true). These two phenomena allow us to analyze the meanings of nouns, adjectives, verbs, adverbs, quantifiers, tenses and the sentences that contain these expressions.