As the previous chapter made clear, in the present interpretation quantum mechanics gives a rather specific account of EPR-type correlations and what underlies them. In the present chapter I argue that this account is genuinely explanatory (rather than merely an idle overlay on a simple description of the observed correlations), and that this constitutes a significant advantage of the present interpretation over certain rival interpretations, on which quantum mechanics is unable to offer an adequate explanation of the observed correlations. In order to make this argument it will prove necessary to examine the character of causal explanation in theoretical science, and in particular to develop a coherent metaphysics of a kind of holistic, nonseparable, causal explanation. I take the development of such a coherent metaphysics to constitute a significant task independent of the details of the present interpretation of quantum mechanics. Quantum mechanics is a mine of metaphysical insights, and I hope here at least to have exposed a rich seam.

The first task is to defend the adequacy of the present account of EPR-type correlations as at least a coherent description of what may underlie the observed correlations. I foresee three main challenges to its descriptive adequacy. The first is to claim that the account is incompatible with the relativistic requirement that there can be no direct causal connection between spacelike-separated events, and must therefore be rejected. A weaker version of this challenge is to claim that although the incompatibility just mentioned may not by itself entail rejection of the account, it does seriously undermine its claim to be genuinely explanatory.