 Now some such arguments seek merely to demonstrate this impossibility without offering any further explanation for it. And it may be contended that most of the arguments of this sort which are at all compelling involve appealing to the obvious impossibility that an event might prevent its own occurrence, and to the slightly less obvious impossibility that an event might bring about its own occurrence. But, in reply to such arguments, it may be claimed that these impossibilities are not sufficient to rule out the possibility that one event might bring about an earlier event, as long as the world is so organised as to avoid these impossible outcomes. If so, it is not clear why God should not have so organised it. And in particular it is not clear why God should not have so organised things that it is possible for us to do things which affect what beliefs he holds.