Carolyn Price investigates what it means to say that mental states -- thoughts, wishes, perceptual experiences, and so on -- are about things in the world. Her answer to this deep philosophical problem is a novel teleological account of intentional content, grounded in and shaped by a carefully constructed theory of functions. Price's teleological account centres on the claim that the content of an intentional state depends both on the information that it is supposed to carry and on the way in which it is used -- whether to trigger a simple response, to help keep track of an object or place, to help in planning a route through the environment, or in a sophisticated process of reasoning. Along the way she defends her view from recent objections to teleological theories, and indicates how it might be applied to some notable problems in the philosophy of mind.Functions in Mind is an adventurous comtribution to the project of bringing together philosophy and biology in order to understand the mind as part of the natural world.