 One strategy for answering this question, which centers on non-epistemic forms of necessity, starts from a certain conception of what (non-epistemic) necessity consists in: for a proposition to be necessary is for its truth to be, in a certain sense, particularly secure, unshakable, and unconditional in a wholly objective way. A necessary truth could not easily have been false (it could less easily have been false than a contingent truth). We may call this feature of a proposition ‘modal force.’ It is natural to apply this conception to metaphysical and nomic necessity. Each of these properties may be held to consist in having a certain grade of modal force, though if contingentism is true, the degree of modal force required for nomic necessity is lower than that required for metaphysical necessity. We could then say that a property is one of the fundamental forms of necessity just in case a proposition \(P\)’s possessing that property consists entirely in \(P\)’s having a specific grade of modal force. Other kinds of necessity, like those listed in (6) can be defined from the fundamental ones by relativization or restriction. Having these properties does not consist simply in having a specific grade of modal force (and these properties therefore aren’t among the fundamental kinds of necessity). For example, if a property is defined by relativizing metaphysical necessity to a class of propositions \(S\), then the fact that a proposition \(P\) has that property consists in the fact that the connection between \(S\) and \(P\) has a certain grade of modal force. But that is not the same thing as P itself having a certain grade of modal force. Similarly, if a property is defined from, say, metaphysical necessity by restriction, then having that property does not consist merely in possessing such-and-such a grade of modal force, but in the conjunction of that feature with some other property.