Is theism a simple hypothesis? The simplicity of omni-properties CALUM MILLER St Hugh’s College, University of Oxford, OX2 6LE, UK e-mail: c.miller@oxon.org Abstract: One reason for thinking that theism is a relatively simple theory – and that it is thereby more likely to be true than other theories, ceteris paribus – is to insist that infinite degrees of properties are simpler than extremely large, finite degrees of properties. This defence of theism has been championed by Richard Swinburne in recent years. I outline the objections to this line of argument present in the literature, and suggest some novel resources open to Swinburne in defence. I then argue that scientists’ preference for universal nomological propositions constitutes a very strong reason for supposing that theism is simpler than parodical alternatives in virtue of its positing omni-properties rather than parallel ‘mega-properties’. Introduction One way of appraising the rationality of theistic belief is to appeal to theism as a theory purporting to explain certain features of the world. Various kinds of reasoning – deductive, inductive, abductive, and probabilistic – have been employed to characterize theism as a theory and identify its theoretical virtues. Whether this approach to theism is a kind of scientific reasoning or is merely similar to scientific reasoning is not a question I will answer here, but the simi- larities are nevertheless instructive. While there is no overwhelming consensus regarding theoretical virtues – and especially regarding their measurement – there is substantial agreement at some junctures. For example, it is generally agreed that simpler or more parsimonious theories are better than less simple theories, ceteris paribus. Whether or not a theory does a good job of explaining our available body of evidence – and, in par- ticular, a diverse and otherwise surprising body of evidence – is also relevant to our overall appraisal of a theory. Religious Studies (2016) 52, 45–61 © Cambridge University Press 2015 doi:10.1017/S0034412514000523  available at http:/www.cambridge.org/core/terms. http://dx.doi.org/10.1017/S0034412514000523 Downloaded from http:/www.cambridge.org/core. The University of Manchester Library, on 22 Oct 2016 at 22:26:02, subject to the Cambridge Core terms of use,