 Within the metaphysical project the vagueness challenge arguably looms especially large for defenders of metaphysically “rich” causal notions, such as notions of causal production. Here the challenge may be part of more general empiricist scruples about rich causal notions of production or “bringing about” along the lines of what has traditionally been taken to be Hume’s criticism of causation. Yet the vagueness challenge can also be presented as a challenge to broadly Humean accounts of causation, such as David Lewis’s account (Lewis 1973).