Salience and Metaphysical Explanation

Metaphysical explanations, unlike many other kinds of explanation, are standardly thought to be insensitive to our epistemic situation and so are not evaluable by cognitive values such as salience. I consider a case study that challenges this view. Some properties are distributed over an extension. For example, the property of being polka-dotted red on white, when instantiated, is distributed over a surface. Similar properties have been put to work in a variety of explanatory tasks in recent metaphysics, including: providing an analysis of change, giving to presentists truthmakers for past claims; giving to priority monists an account of basic heterogeneous entities; and giving to friends of extended simples an explanation of how an extended simple can enjoy qualitative variation. I argue that such explanations exhibit salience failure. How ought we represent the semantics of salience? Differences in linguistic stress induce semantic differences similar to the semantic differences induced in explanations by differences in salience, and I will draw an analogy with linguistic theories of focus sensitivity to sketch how one might model the role of salience in these kinds of explanations. I end with a few tentative conclusions about the role of cognitive values in metaphysical explanations. Some theorists view the citation of a ground as a sufficient explanation. If certain explanations appealing to distributed properties exhibit attenuated salience, then arguably the mere citation of a ground does not always provide an adequate explanation.