Jaegwon Kim maintains that his ‘exclusion argument’ forces us to accept reductive physicalism, which identifies mental and other high-level properties of the world with lower-level properties, over nonreductive physicalism, which avoids such identifications. According to Kim, the exclusion argument shows that any nonreductive view leads to either epiphenomenalism or unacceptable overdetermination of physical effects by physical causes. However, a popular nonreductive physicalist approach called ‘compatibilism’ aims to show that physicalism need not collapse high-level properties into lower-level physical. Compatibilism attempts to (...) block the exclusion argument by attending to the tight modal relationship between higher and lower properties required by nonreductive physicalism. Unfortunately, a similarly tight modal relationship will be embraced by any dualists who hold that natural laws are metaphysically necessary. Despite its increasingly widespread popularity among nonreductive physicalists, it thus seems that the compatibilist’s proposed solution cannot be upheld without removing the barriers to dualists of this sort. (shrink)