Nothing can be temporally prior to a series of causes and effects that has no beginning or exists for eternity.

The step in this argument that seems most questionable is the claim that because each element in the causal chain has been explained, in terms of some earlier member of the chain, we have “sufficiently explained” why there exists any such chain or why this particular chain exists. Critics will argue that this has plainly not been done. One response to this is argue that it is a philosophical mistake to look for an explanation of this kind, on the ground that a cause must be prior to its effect i