 It is open to debate which kinds of necessity are fundamental, in the sense that all others can be defined in terms of them, while they are not themselves definable in terms of others. The monist view considered in  section 1.3,  when combined with (7), may inspire the hope that we can make do with a single fundamental kind of necessity. Others have argued that there are several kinds of necessity that are not mutually reducible. For example, Fine (2002) suggests (in a discussion that sets aside epistemic modality) that there are three fundamental kinds of necessity, which he calls ‘metaphysical,’ ‘nomic’ and ‘normative’ necessity. (For further discussion of normative necessity, see Rosen 2020.)