a technology, and that human descendants will have no overriding legal restrictions or moral compunctions against simulating biospheres or their own historical biosphere, then, Bostrom argues it would be unreasonable to count ourselves among the small minority of genuine organisms who, sooner or later, will be vastly outnumbered by artificial simulations. Epistemologically, it is not impossible to tell whether we are living in a simulation. For example, Bostrom suggests that a window could pop up saying: "You are living in a simulation. Click here for more information." However, imperfections in a simulated environment might be difficult for the native inhabitants to identify and for purposes of authenticity, even the simulated memory of a blatant revelation might be purged programmatically. Nonetheless, should any evidence come to light, either for or against the skeptical hypothesis, it would radically alter the aforementioned probability. Computationalism Computationalism is a philosophy of mind theory stating that cognition is a form of computation. It is relevant to the simulation hypothesis in that it illustrates how a simulation could contain conscious subjects, as required by a "virtual people" simulation. For example, it is well known that physical systems can be simulated to some degree of accuracy. If computationalism is correct and if there is no problem in generating artificial consciousness or cognition, it would establish the theoretical possibility of a simulated reality. Nevertheless, the relationship between cognition and phenomenal qualia of consciousness is disputed. It is possible that consciousness requires a vital substrate that a computer cannot provide and that simulated people, while behaving appropriately, would be philosophical zombies. This would undermine Nick Bostrom's simulation argument; we cannot be a simulated consciousness, if consciousness, as we know it, cannot be simulated. The skeptical hypothesis remains intact, however, and we could still be vatted brains, existing as conscious beings within a simulated environment, even if consciousness cannot be simulated. It has been suggested that whereas virtual reality would enable a participant to experience only three senses (sight, sound and optionally smell), simulated reality would enable all five (including taste and touch). Some theorists have argued that if the "consciousness-is-computation" version of computationalism and mathematical realism (or radical mathematical Platonism) are true then consciousnesses is computation, which in principle is platform independent and thus admits of simulation. This argument states that a "Platonic realm" or ultimate ensemble would contain every algorithm, including those that implement consciousness. Hans Moravec has explored