Monism is our name for a range of views according to which the connection between dispositions and their categorical bases is intimate and necessary, or on which there are no categorical bases at all. In contrast, Dualist views hold that the connection between dispositions and their categorical bases is distant and contingent. This paper is a defence of Monism against an influential conceivability argument in favour of Dualism. The argument suggests that the apparent possibility of causal behaviour coming apart from (...) categorical bases is best explained by Dualism. We argue that Monism can explain the apparent possibility as well, if we take metaphysically alien laws — namely, laws whose metaphysical nature is alien to the actual world — into account. (shrink)