The author describes an interpreted modal language and produces some clear examples of logical and analytic truths that are not necessary. These examples: (a) are far simpler than the ones cited in the literature, (b) show that a popular conception of logical truth in modal languages is incorrect, and (c) show that there are contingent truths knowable ``a priori'' that do not depend on fixing the reference of a term.

The paper introduces a contingential language extended with a propositional constant τ axiomatized in a system named KΔτ , which receives a semantical analysis via relational models. A definition of the necessity operator in terms of Δ and τ allows proving (i) that KΔτ is equivalent to a modal system named K□τ (ii) that both KΔτ and K□τ are tableau-decidable and complete with respect to the defined relational semantics (iii) that the modal τ -free fragment of KΔτ is exactly the (...) deontic system KD. In §4 it is proved that the modal τ -free fragment of a system KΔτw weaker than KΔτ is exactly the minimal normal system K. (shrink)

Metaphysics, as I understand it, is the attempt to construct theories which give correct accounts in general terms of pervasive structural features of reality. Though not precise and not intended as an explicit definition, this characterization is comprehensive enough to include both descriptive and revisionary varieties of metaphysical theory. The enterprise of descriptive metaphysics, Strawson tells us, consists in describing “the actual structure of our thought about the world.” Presumably a philosopher would favor this approach to metaphysics if he or (...) she believed either that the actual structure of our thought about the world provides, at least for the most part, an accurate portrait of the world’s structure or that the actual structure of our thought at any time provides privileged access, or perhaps our only access, at that time to the structure of the world. Revisionary metaphysics, by contrast, is concerned to produce a structure of thought about the world better than the one we actually have. Obviously a philosopher would adopt this approach if he or she believed that the actual structure of our thought about the world provides, in at least some important respects, an inaccurate portrait of the world’s structure and stands in need of revision in the interests of correctness. And clearly a philosopher might hold that the actual structure of our thought is quite accurate in some respects and need only be described to yield correct theory and yet is thoroughly inaccurate in others and requires substantial revision if correct theory is to be the outcome. Philosophers may, as I suppose most of them do, practice by turns descriptive and revisionary kinds of metaphysics. No global commitment to one approach or the other is required; the choice between approaches can be allowed to rest on the exigencies of local problems. (shrink)