 Compatibilists should solve what Frank Jackson calls ‘the location problem’ (Jackson 1998). If you think that there are, say, beliefs, and you think that having beliefs in one’s metaphysics doesn’t commit you to having anything in your ontology beyond fundamental physics, then you should, as Jackson puts it, be able to locate beliefs in the world described by fundamental physics. More generally, for whatever you accept, you should be able to locate it in the picture of the world you accept.