 It’s worth reflecting on the difference between the epistemic regress and the ontological regress of dependent entities that makes Klein’s response here possible. Suppose that \(A\) is ontologically dependent on \(B\) and \(B\) ontologically dependent on \(C\). It is very plausible that in this case, \(C\)’s existence and/or nature is part of the explanation of \(A\)’s existence and/or nature. In saying that \(A\) is ontologically dependent on \(B\) we are saying that \(A\) exists, or is the way it is, at least partly in virtue of \(B\)’s existence and/or nature. So \(B\) has to exist, or be the way it is, in order for \(A\) to exist, or be the way it is. In explaining \(A\)’s existence/nature, we are appealing to \(B\)’s existence/nature, in which case it seems that anything that we need to explain \(B\)’s existence and/or nature—in this case \(C\)’s existence/nature—must ultimately be part of the explanation of \(A\)’s existence and/or nature. That’s why when we have a chain of ontological dependence, the existence and/or nature of the first entity seems to be ultimately dependent on not just the existence/nature of the second entity in the chain, but on that of every subsequent entity in the chain: explanations of being appear to be transmissive. Which is why, if the chain is endless, we seem to lack an explanation as to why anything exists at all.