James Willoughby, "Revising The Revisionist Story"

(3.30pm - 4.30pm)

Revisionist philosophical theories face an up-hill battle. They deviate from the way the world seems, from our intuitions, from our folk theories, from the common sense view, from the natural things to think, from our pre-theoretic judgments, from our basic beliefs. The traditional story is that when a philosophical theory deviates from the way the world seems, there is an epistemic cost to the theory. Similarly, when a theory conforms to the way the world seems, there is an epistemic credit to the theory. All other things being equal, it is a cost to deviate and a credit to conform. So, according to the traditional story, revisionist theories necessarily incur an epistemic debt from the start because they deviate and their non-revisionist counterparts conform. I argue that the traditional story is false. It is not always a cost to deviate and a credit to conform. The way the world seems is the product of a messy evolutionary process. It is very unlikely that the product of such a messy process is completely accurate. So we should expect true philosophical theories to deviate from the way the world seems. We should aim for revisionist theories and be suspicious of theories that conform too much.

Lachlan Walmsley, "Intervening on Frodo: Mathematical objects, fictional worlds, and virtual slime"

(4.30pm - 5.30pm)

Here are two theories of scientific models. According to one, models are interpreted structures, so mathematical models are abstract objects, like a trajectory through a multi-dimensional phase space, which are mapped onto some actual or hypothetical target system (Weisberg). According to another, mathematical models fictional worlds—think Tolkein’s Middle Earth—rather than abstract objects (Godfrey-Smith). In this talk, I’ll give some reasons for picking the first theory. For one thing, models qua mathematical objects are rule-governed in ways the fictional worlds are not, permitting systematic manipulation and the generation of counterfactuals. I won’t be following Weisberg in relegating the idea of models as fictions to a mere part of scientists’ “folk ontology,” however. Rather, I’ll suggest that Godfrey-Smith’s framework gets more traction in cases of computer simulation in which visualisation of virtual entities plays a key role.