title:	The role of salience in the emergence of signalling conventions
author(s):	Robert Sugden
affiliation:
time and place:	Wednesday, 14.00 - 17.00, room A In the thematic session on Games in Logic and Language
abstract:	In Convention, David Lewis argues that languages can be understood as conventions. His argument works by showing that conventions by which particular signs indicate particular meanings can emerge as equilibrium solutions to signalling games (a sub-class of coordination games), and by arguing that such conventions are rudimentary languages. A possible criticism of this argument is that Lewis's theory assumes that the players of signalling games share common conceptions of salience; if the existence of such common conceptions depends on the prior existence of a language community, Lewis has not explained language 'from outside'. In Evolution of the Social Contract, Brian Skyrms claims to resolve this problem by reconstructing Lewis's model in a way that dispenses with salience; conventions evolve within a population of inductive learners by the amplication of initially random variations. I argue that Skyrms fails to take account of the problem that led Lewis to invoke salience: the unlimited number of potential signals. If there is an infinity of conceivable regularities in experience, inductive learning requires the prior privileging of a small number of these regularities as ones that, if observed, would count as patterns and not as random noise. Thus, inductive learning depends on a form of salience. However, the common conceptions of salience necessary for the emergence of signalling conventions do not require the prior existence of a language community.