We discuss some ideas about what "possible worlds" might be, partly to elucidate the character of logical necessity, and partly as an approach to metaphysics and the philosophy of science.

Notes on space and time and the theory of relativity.

I am at present thinking about physics from two distinct but connected points of view. I am first of all trying to understand the world, as a philosopher might, as it is described by modern physics. Secondly I am trying to understand how to formalise physics and also perhaps to make some progress towards achieving a formalisation. As befits a primarily philosophical enterprise, my conception of it is vague and fluid. This is my best attempt to present the entrprise as I think of it at present.

A philosophical discussion of metaphysical ontology.

Physics is concerned with an understanding of the Universe, and is an empirical or experimental science. Physics is therefore concerned with truths about the world which may be discovered by observation.

Metaphysics is concerned with a philosophical understanding of the world as distinct from a scientific understanding. This may be a kind of understanding which is prerequisite to empirical enquiry, or it may represent a perspective on the kinds of results which the physicist might of obtain, perhaps taking the view that things are not as they appear to empirical science.

The metaphysical position we adopt is engineered to provide a philosophical account consistent with the view of science as constructing conceptual or mathematical models of the world which are judged (in part) by their predictive capabilities.

Any finite set of observations will be consistent with the predictions obtained from a variety of mathematical models. Even if a model is known to be perfectly consistent with all the experimental data it may therefore not unambiguously establish the structure of the world. We therefore take the position that the ultimate nature of reality is beyond our reach.

Metaphysics sits on the common boundary of the fundamental triple-dichotomy between analytic/synthetic, necessary/contingent and a priori/a posteriori knowledge.

It is often claimed that modern physics has delivered radical changes to our conception of space and time through the special and general theories of relativity. However, for the philosophically minded lay person wishing to understand this better, difficulties arise. It is my purpose here simply to note the difficulties which seem to me to arise. To articulate certain questions to which I have not yet been able to discover an answer.

Since the formulation of Einstein's theories of relativity the nature of space-time has been firmly within the scope of science. Or has it?

The antithesis is not watertight, synthesis uncertain, questions remain.

It may be argued that fundamental theories in physics go beyond the facts in various ways. We discuss here some ideas about how they do that and how one might attempt to separate out the hard content of a theory from these more difficult areas.

On the nature of the enterprise and the distinction between abstract and concrete ontology.