Our natural human intuition testifies to the metaphysical impossibility of an events occurring uncaused.1, 2 This is relevant because our natural human intuitions rationally ought to be given benefit of the doubt.
“Although Borde and Vilenkin [overturned Linde's own attempt to avert a beginning], they did not conclude that the question of the origin of the universe was therefore a pseudoproblem; rather they wrote, 'The fact that inflationary spacetimes are past incomplete forces one to address the question of what, if anything, came before.' The fact is that a whole series of cosmological models have been proposed over the last halfcentury specifically to avoid the absolute beginning predicted by the Standard Model. Both philosophers and physicists have been deeply disturbed at the prospect of a beginning of time and an absolute origination of the universe and so have felt constrained to posit the existence of causally prior entities like quantum vacuum states, inflationary domains, imaginary time regimes, and even timelike causal loops.” [“Must the Beginning of the Universe Have a Personal Cause?: A Rejoinder”, Faith and Philosophy 19, no. 1 (2002): 96]
In our uniform and repeated experience, all events so far are caused to occur.1 This is relevant because extrapolative inference (inductive reasoning) is a legitimate way here to accumulate evidence for the causal principle.
But, so what? Couldn't it simply be that such an inference “overgeneralizes”?2 [See response]3
Quantum mechanical events furnish counter-examples to the causal principle.1
But wait, these events are caused, it is just that they are caused indeterminstically.2 They certainly do not come from nothing/non-being (virtual particles are no exception).3
The notion of an uncaused event seems logically consistent.1
But wait, a state-of-affairs need not be logically impossible (free of formal contradictions) to be metaphysically impossible.2