The Fragmented Mind: Belief, Rationality, and Agency

This project will investigate and develop the hypothesis that the human mind belief in particular is fragmented; it will use this hypothesis to solve a number of outstanding problems and puzzles in philosophy. Fragmentation (regarding belief) holds that a single agent has various separate systems of belief, which need not make for a logically consistent and deductively closed overall system. That is, an agent may have a number of beliefs in one fragment, while having other beliefs in another fragment, without drawing connections between these fragments. The contrary view a dogma widely adhered to in philosophy that also underlies many formal models of belief and decision- making has it that the human mind is unified: that a single agent`s total belief set is consistent and includes its deductive consequences. This assumption of unity faces grave problems: (i) As a descriptive thesis, it is a blatant mischaracterization of the reality of human belief and its connection to agency; it is easy to show that real agents are not always consistent in their beliefs and do not believe all the deductive consequences of their beliefs. (ii) As a normative thesis about ideal rationality, unity leads to notorious problems and paradoxes, such as the preface paradox, the problem of deduction and we argue Freges puzzle. The aim of the project is to develop a psychologically substantive theory of fragmentation. The project proposes to offer a viable alternative to the dogma of unity, thus solving a variety of prominent puzzle cases that beset both descriptive and normative versions of unity. It will thereby (a) shape and significantly advance an important new research area fragmentation; (b) contribute to solving a number of perennial problems in philosophy of mind, epistemology, and philosophy of language; and (c) bring together and relate the isolated debates in which these problems have been treated.