Title: The Hyperintensional Mind

Abstract: Agents do not automatically believe all the necessary equivalents of the things they believe; and they do not always desire necessary equivalents to the same degree. Mental contents must be distinguished in a more fine-grained way (“hyperintensionally” rather than “merely intensionally”). Doing so faces a foundational challenge, however. One influential functionalist or “analytic functionalist” picture of offers an account of the contents of agents’ attitudes in terms of agents’ behaviour across variations in possible circumstances. This “modalist” picture is usually involves a commitment to treating contents as sets of possible worlds, sets of possible individuals, or some sort of construction out of these. This paper will argue that a modalist approach can be attractively developed to handle a richer range of contents, provided we equip ourselves with hyperintensional metaphysical resources. The resulting understanding suggests a picture of contents as sets of worlds rather than as structured contents, and offers some guidance on the question of the fine-grainedness of belief and desire.