This paper presents a new argument for necessitism, the claim that necessarily everything is necessarily something. The argument appeals to principles about the metaphysics of quantification and predication which are best seen as constraints on reality's fineness of grain. I give this argument in section 4; the impatient reader may skip directly there. Sections 1-3 set the stage by surveying three other arguments for necessitism. I argue that none of them are persuasive, but I think it is illuminating to consider my argument in light of the others and vice versa. These interconnections should be of interest even to those who reject necessitism; of particular interest may be the new conception of validity proposed in section 5.
Combining LogicsFollowing Williamson (2013), let necessitism be the claim expressed by the formula NNE ∀x ∃y(y = x) when is read as expressing the kind of 'metaphysical' necessity familiar from Kripke (1972) and the quantifiers are read as unrestricted. One sometimes hears that necessitism falls out of the combination of classical quantification theory and standard propositional modal logic. In this section I will explain one sense in which this is true and argue that it does not support a persuasive argument for necessitism.By a logic I will mean a set of sentences of some formal language. Logics are usually specified in two steps. First, we write down some axiom schemata. Second, we define our logic to be the smallest set of sentences of our formal language that both contains every instance of any of the specified schemata and satisfies certain closure conditions. The closure conditions are sometimes called 'rules of inference', but we should not mistake them for prescriptions about how to reason: they are simply properties of sets. Call this way of specifying a logic axiomatization.