The microstructural causation hypothesis

I argue against a priori objections to the view that causation may be reducible to some micro-structural process in principle discoverable by physics. I distinguish explanation from causation, and argue that the main objections to such a reduction stem from conflating these two notions. Explanation is the collection of pragmatically relevant, possibly counterfactual information about causation; and causation is to be identified in a necessary a posteriori way with whatever physical processes underwrite our explanatory claims.I am grateful to Frank Jackson, Oscar Manhal, Peter Menzies, Philip Pettit and Huw Price for comments on earlier drafts of this paper. Since an earlier draft, I have heard of the death of Oscar Manhal. Oscar did not agree with the line defended here; but it is better defended for his disagreement. He will be greatly missed.