John Divers

We outline a theory of the cognitive role of belief in absolute necessity that is normative and intended to be metaphysically neutral. We take this theory to be unique in scope since it addresses simultaneously the questions of how such belief is (properly) acquired and of how it is (properly) manifest. The acquisition and manifestation conditions for belief in absolute necessity are given univocally, in terms of complex higher-order attitudes involving two distinct kinds of supposition (A-supposing and C-supposing). It is subsequently argued that the proposed acquisition and manifestation conditions are rationally interdependent, and that such harmony affords explanations of connections between different facets of belief in necessity that otherwise remain mysterious.

The modal primitivist who takes a sentential possibility operator as her only modal resource can provide adequate representations of the familiar concepts of weak, strong and global supervenience. The primitivist representations of these concepts can be applied to provide adequate interpretations of speciflc supervenience theses which will be considered. Moreover the modal primitivist is no better and no worse placed than the genuine modal realist to present supervenience as a simple and unifled notion. Therefore, Lewis is unjustified in claiming that a genuine modal realist approach to the analysis of the concept of supervenience is superior to a modal primitivist approach.

Kant states that necessity and strict universality are criteria of a priori knowledge. Interpreting this dictum standardly and straightforwardly in respect of necessity, it is inconsistent with there being necessary a posteriori truths or contingent a priori truths (cf Kripke). This straightforward interpretation may convict Kant of understandable error (at worst) in the case of necessity, but it is so uncharitable in the case of strict universality that we ought to seek an alternative. I offer a charitable interpretation of the doctrine that necessity and strict universality are sufficient conditions of a priority, commenting briefly on comparable necessary conditions.

In this reply, we defend our argument for the incompleteness of Genuine Modal Realism against Paseau's criticisms. Paseau claims that isomorphic set of worlds represent the same possibilities, but not only is this implausible, it is inimical to the target of our paper: Lewis's theory of possible worlds. We argue that neither Paseau's model-theoretic results nor his comparison to arithmetic carry over to GMR. We end by distinguishing two notions of incompleteness and urge that, for all that Paseau has said, GMR remains incomplete in the relevant sense.

In section 1 I motivate and execute the presentation of a well-defined Lewisian conception of analysis and of what it would be to analyse modality successfully. That conception is then put to two applications. In section 2 various inadequacies are exposed in a (recently popular) separatist approach to the understanding and/or evaluation of Lewis's analysis of modality. Section 3 provides a defence against a resilient argument for the claim that Lewis's analysis of modality cannot be fully reductive while also dealing adequately with alien possibility.

If a possible-worlds semantic theory for modal logics is pure, then the assertion of the theory, taken at face-value, can bring no commitment to the existence of a plurality of possible worlds (genuine or ersatz). But if we consider an applied theory (an application of the pure theory) in which the elements of the models are required to be possible worlds, then assertion of such a theory, taken at face-value, does appear to bring commitment to the existence of a plurality of possible worlds. Or at least that is so if the applied theory is adequate. For an applied possible-worlds semantic theory that is constrained to contain only one-world models is bound to deliver results on validity, soundness and completeness that are apt to seem disastrous. I attempt to steer a course between commitment to the existence of a plurality of possible worlds and commitment to such a disastrous applied possible-worlds semantics by noting, and developing, the position of one who asserts such a theory at face-value but who remains agnostic about the existence of other (non-actualized) possible worlds. Thus, a novel interpretation of applied possible-worlds semantics is offered on which we may lay claim to whatever benefits such a theory offers while avoiding realism about (other) possible worlds. Thereby, the contention that applied possible-worlds semantics gives us reason to be realists about possible worlds is (further) undermined.

This chapter has three principal aims. Firstly, to promote interest in the question of the function, or utility, of judgements of modality. Secondly, to endorse an alternative to orthodox contemporary methodology, advocating that we prioritize the question of function in modal philosophy. Thirdly, to consider among our modal judgements exactly which are the proper and exact source of various different kinds of substantial philosophical commitments in ontology, epistemology, and elsewhere. An illustration is offered, in the de dicto case, of how minimal a philosophical theory of modality might be if constructed properly, and carefully, according to functional methodology.

Colin McGinn proposes that acceptance of the supervenience of the modal on the actual is the natural form of expression of a non-objectual realism about modality. Here, some of the difficulties that arise in applying theses of supervenience to the modal-actual case are discussed. It is then argued: 1)that the truth of many such theses is determined on uncontroversial modal logical and conceptual grounds, and 2) that this and other independent considerations render it highly implausible that the affirmation of modal-actual supervenience amounts to a modal realism.