Models of Science and the Role of Causation Aaron L Bramson June 14, 2007 Let us chace our imagination to the heavens, or to the utmost limits of the universe; we never really advance a step beyond ourselves, nor can conceive any kind of existence, but those perceptions, which have appear’d in that narrow compass. This is the universe of the imagination, nor have we any idea but what is there produc’d. -Hume (Treatise I.2.6) Abstract Hume calls causation “the cement of the universe” which seems to imply that there is a universe “out there” and it needs causation to hold it together (though it seems highly unlikely that Hume himself held such a view). The position argued for here is that for some reason our perceptions admit to regularities that we encode into models and the behavior of models is entirely determined by such rules and so these rules really do hold these models together. Because we completely rely on (explicit and implicit) mental models to govern our behavior and understanding we project some of these rules into the world in the form of causes. Realizing that our concept of causation applies only to our models, and taking the skeptical thesis seriously that models are all we really have, we gain a concept of causation that does all the work it previously did to relate events but does not depend on an external world that may not be there. 1