Abstract

Sentences can be thought of as expressing propositions or statements. The logical nominalist is right, against the logical Platonist, to hold that propositions and statements are not really existing things but mere useful fictions. A sentence is logically necessary if its negation entails a contradiction, given that its referring expressions in fact pick out the objects that they do. A sentence's entailments are a matter of the human conventions for the use of that sentence. There are kinds of necessity other than logical necessity. In particular, there is what I call ‘ontological necessity’ – everlasting uncaused existence; and what I call ‘metaphysical necessary’. Something is metaphysically necessary in my sense if either it is ontologically necessary or it is inevitably caused to exist everlastingly by something ontologically necessary.