 To say merely that the \(F\)-ness of each \(X\) is explained by appeal to another \(X\) that is \(F\) leaves open a crucial question: does the \(F\)-ness of the new \(X\) play a role in the explanation of the \(F\)-ness of the initial \(X\)? Following Bob Hale (2002), let’s distinguish between transmissive explanations of \(F\)-ness, in which the \(F\)-ness of \(X_2\) plays a crucial role in explaining the fact that \(X_1\) is \(F\), the \(F\)-ness of \(X_3\) plays a crucial role in explaining the fact that \(X_2\) is \(F\), and so on, from non-transmissive explanations of \(F\)-ness, in which the \(F\)-ness of \(X_1\) is explained by facts concerning \(X_2\), which is in fact \(F\), but where the \(F\)-ness of \(X_2\) is not crucial to explaining the \(F\)-ness of \(X_1\), and so on. Arguably an infinite regress of transmissive explanations of \(F\)-ness leaves unexplained why anything is \(F\) in the first place, but an infinite regress of non-transmissive explanations need not.