Evolving Perceptual Categories **Draft, do not cite**

Hume’s scepticism was based, in part, on what he believed to be an inability of human observers to ever go beyond their perceptual experiences. How can an observer determine the veridicality of perception when her only access to the external world is mediated by perception itself? A related question may be asked about not the qualities of perception, but about the perceptual categories of biological actors. How can one reach beyond perception to determine whether and to what degree perceptual categories—sweet, green, cool—track properties of the world around them? Jäger (2007) introduced a set of modified signaling games—‘sim-max games’—that can help address this problem. Sim-max games assume that actors are transferring information about states of the world that bear underlying similarity relations to one another. What this alteration means is that, unlike in a traditional Lewis signaling game, there is a natural sense in which actors might want to categorize groups of states together in order to transfer meaning about them. This paper will use sim-max games to discuss a philosophical question related to that mentioned above: to what degree should we expect the perceptual categorizations of biological actors to track properties of the world around them? Results from sim-max games seem to suggest that optimal perceptual categories are convex, and are thus, in a sense, natural. The sense in which categories are convex, however, depends entirely on payoff to the actors in the game, rather than some underlying structure of the world. Thus, it might be argued that