Nick Bostrom, Director of the Future of Humanity Institute (Oxford University) has an interesting arguement about the nature of reality. The basic idea is simple: when you consider whether we are brain-in-a-bottle simulations or not, there are only three possibilities - and one of them must be true. It's an interesting perspective, and it might even be testable - which takes it from philosophy to science.
ABSTRACT. This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor-simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.