The Rules of Thought develops a rationalist theory of mental content while defending a traditional epistemology of philosophy. Jonathan Jenkins Ichikawa and Benjamin W. Jarvis contend that a capacity for pure rational thought is fundamental to mental content itself and underwrites our quotidian reasoning and extraordinary philosophical engagement alike. Part I of the book develops a Fregean theory of mental content, according to which rational relations between propositions play a central role in individuating contents; the theory is designed to be sensitive t only to Frege's puzzle and other data that have motivated rationalist conceptions of content, but also to considerations in the philosophy of mind and language that have motivated neo-Russellian views. Part II articulates a theory of the a priori, and shows that, given the framework of Part I, it is very plausible that much philosophical work of interest is genuinely a priori. Notably, it is part of the picture developed that intuitions have an important role to play, either in mental content, or in the epistemology of the a priori; Part III defends this departure from rationalist orthodoxy.
Jonathan Jenkins Ichikawa is an assistant professor of philosophy at the University of British Columbia; he did his graduate work at Brown University and Rutgers University and post-doctoral work at the Arche Research Centre in St Andrews. He works primarily in epistemology and philosophical methodology; he has written papers on dreaming, imagination, knowledge and knowledge attributions, intuitions, and experimental philosophy. ; Benjamin W. Jarvis received his PhD in philosophy from Brown University in 2010, taking up a permanent lectureship in philosophy at Queen's University Belfast that same year. He works primarily in epistemology and the philosophy of mind and cognitive science and has published papers on belief, mental representation, knowledge, and truth.