Representation and rationality

David Lewis (1974, 1994/1999) proposed to reduce the facts about mental representation sensory evidence, dispositions act, and rationality. Recently, Robert Williams (2020) Adam Pautz (2021) have taken up developed Lewis's project in sophisticated novel ways. In this paper, we aim present, clarify, ultimately object core thesis that they all build their own views around. The different developments defenses notwithstanding, think is vulnerable. We pose a dilemma by considering two sides of current epistemological controversy over relation between evidence rational belief: permissivism vs. uniqueness. As argue, prospects for Lewisian look dim when either supposition clearly made.