Logical Spillover

Abstract

In this chapter I focus on a different ways in which logical regions can interact. If folded logical space was the idea that some regions overlap via transistence or transistent causation, the idea of logical spillover is that the way things stand within one region, R, will force us to draw conclusions about the entire canonical logical space that R is part of. This phenomenon will be most useful when R is the actual region or actual world, because our knowledge of some actual facts will determine our view about some modal facts. The idea that how things actually are guides what we should say about how things could have been is, of course, not new. Saul Kripke’s celebrated work, Naming and Necessity, offers highly credible arguments to the effect that, say, if water is actually H₂O, then in all possible worlds water is H₂O, any world that appear as containing water that is not H₂O is to be accounted for as a world containing something that resembles water but is a distinct kind. However, I put forward another way in which logical spillover can manifest itself, namely, when the way we deduce how the entire canonical logical space must look like is based on probabilistic considerations.