 It is, of course, possible that the fatalist challenge about the difference between the future and the present and past cannot be successfully met. For instance, it could be argued (a) that the only successful answer would be one which appealed to a fundamental ontological distinction between the future and the present and past, but that (b) there is in fact no such distinction (Shanks 1994; discussed in Oaklander 1998). But, as we have noted, even if this challenge cannot be met, it does not show that the fatalist is correct. The possibility remains that we can, in principle, affect the past.