What are the assumptions underlying your assumptions?

“Any conclusions that specialists may draw about the relation of physical discoveries to life come from the whole of life, not just from physics, and are no stronger than their weakest link. Physics itself, moreover, is no self-contained enclave. Its arguments, like all other arguments, involve philosophical presuppositions, ideas that come from outside it. The questions involved in causal problems about the Big Bang are not internal to physics. They are shaped by crucial metaphysical notions about how causality, necessity, space, time, etc. should in general be conceived. Scientists who deal with these questions are doing metaphysics. They are perfectly entitled to do it and indeed must do it for these large, structural purposes. But whether their metaphysics leads them into religious thinking depends on all sorts of considerations internal to it and quite outside physical science itself. There is no short cut.” – Mary Midgley, Science as Salvation