One of the most fundamental tasks of a theory of metaphor is to explain what any given metaphorical utterance says in a way that is compatible with the framework provided by philosophy. Using clear language, this book provides a theory of metaphor in terms of reconceptualization that is compatible with current trends in cognitive linguistics, while being philosophically rigorous in that it remains true to the fundamental philosophical insights into such notions as those of 'meaning' and 'content'. As such, this work serves as a bridge between philosophy and linguistics in the study of natural language. It also provides a detailed critique of respected theories of metaphor, showing how they fall into two camps depending on their account of metaphorical content, and compiling a list of phenomena any theory of metaphor (and thus model of natural language processing) must address.