Online research in philosophy

By the term nominalization I mean any process which transforms a predicate or predicate phrase into a noun or noun phrase, e.g. feminine is transformed into feminity. I call these derivative nouns abstract singular terms. Our aim is to provide a model-theoretic interpretation for a formal language which admits the occurrence of such abstract singular terms.

In The Logical Basis of Metaphysics, Dummett argues at length that Geach has been wrong in taking the sense of a predicate to be a function that sends the sense of a proper name to that of a sentence, and claims that it should instead be a means to determine the referent of the predicate, as is suggested by Frege’s sense-determines-reference (SDR) principle. This disagreement between Dummett and Geach calls for a serious investigation into two of Frege’s sense-related principles, namely the Compositionality thesis and the SDR thesis. By making precise both theses in terms of supervenience, we pin down a preferable sense of compositionality for senses, and resolve the debate in question.

The problematic features of Quine's set theories NF and ML are a result of his replacing the higher-order predicate logic of type theory by a first-order logic of membership, and can be resolved by returning to a second-order logic of predication with nominalized predicates as abstract singular terms. We adopt a modified Fregean position called conceptual realism in which the concepts (unsaturated cognitive structures) that predicates stand for are distinguished from the extensions (or intensions) that their nominalizations denote as singular terms. We argue against Quine's view that predicate quantifiers can be given a referential interpretation only if the entities predicates stand for on such an interpretation are the same as the classes (assuming extensionality) that nominalized predicates denote as singular terms. Quine's alternative of giving predicate quantifiers only a substitutional interpretation is compared with a constructive version of conceptual realism, which with a logic of nominalized predicates is compared with Quine's description of conceptualism as a ramified theory of classes. We argue against Quine's implicit assumption that conceptualism cannot account for impredicative concept-formation and compare holistic conceptual realism with Quine's class Platonism.

How are philosophical questions about what kinds of things there are to be understood and how are they to be answered? This paper defends broadly Fregean answers to these questions. Ontological categories—such as object , property , and relation —are explained in terms of a prior logical categorization of expressions, as singular terms, predicates of varying degree and level, etc. Questions about what kinds of object, property, etc., there are are, on this approach, reduce to questions about truth and logical form: for example, the question whether there are numbers is the question whether there are true atomic statements in which expressions function as singular terms which, if they have reference at all, stand for numbers, and the question whether there are properties of a given type is a question about whether there are meaningful predicates of an appropriate degree and level. This approach is defended against the objection that it must be wrong because makes what there depend on us or our language. Some problems confronting the Fregean approach—including Frege’s notorious paradox of the concept horse—are addressed. It is argued that the approach results in a modest and sober deflationary understanding of ontological commitments.

The history of the idea of predicate is the history of its emancipation. The lesson of this paper is that there are two more steps to take. The first is to recognize that predicates need not have a fixed degree, the second that they can combine with plural terms. We begin by articulating the notion of a multigrade predicate: one that takes variably many arguments. We counter objections to the very idea posed by Peirce, Dummett's Frege, and Strawson. We show that the arguments of a multigrade predicate must be grouped into places, with perhaps several arguments occupying positions at a place. Variability may relate to places or positions. Russell's multiple judgement predicate turns out to be just one example of a family—‘is necessarily true of’, ‘is said of’, ‘is instantiated by’ and so on—of predicates with variably many places. Our main concern, however, is lists. Any adequate account of lists must include plural as well as singular terms. On one account, lists are mere strings of separate arguments, which occupy variably many positions within a place of a multigrade predicate. A quite different account takes the list itself to be a compound plural term. We compare these rival conceptions, and reach some surprising conclusions. As a coda, we deploy the conceptual apparatus developed in the paper to assess Morton's pioneer system of multigrade logic.

Strawson offers three accounts of singular predication: a grammatical, a category and a mediating account. I argue that the grammatical and mediating accounts are refuted by a host of counter-examples and that the latter is worse than useless. In later works Strawson defends only the category account. This account entails that singular terms cannot be predicates; it excludes non-denoting singular terms from being logical subjects, except by means of an ad hoc analogy; it depends upon a notion of identification that is too vague; and it is unnecessarily complicated, relying on analogies where a more uniform explanation should be possible. But I show how the account can be corrected to avoid all these difficulties and to provide an accurate account of singular predication.