Page 57 - Encyclopedia of Philosophy of Language

W. V. O. Quine avoids this mystery by taking the vehicles of ontological commitment to be existential quantifiers rather than names. He suggests the fol- lowing criterion of ontological commitment: 'we are convicted of a particular ontological presupposition if, and only if, the alleged presuppositum has to be reckoned among the entities over which our variables range in order to render one of our affirmations true' (Quine 1980: 13). Or, more tersely, to be is to be the value of a variable. So, for example, mathematics includes the sentence 'there is a prime number which is greater than 1,000.' The existential quantifier in this sentence ranges over prime numbers which must be assumed to exist if this sentence is to be true.
2. What Are Numbers?
The diverse pressures facing an ontology are well illus- trated by the plethora of accounts of number. For example, the goal of Frege's logicist project was to supply an epistemologically secure foundation for arithmetic. Thus Frege attempted to prove arith- metical truths from logic alone by reducing the cat- egory of natural numbers to a category of logical objects: classes. Statements quantifying over numbers were viewed as abbreviating statements quantifying over classes.
But the commitment to classes is epistemologically problematic. In particular, classes, standardly conceived, have neither causes nor effects. Yet knowl- edge seems to require some causal commerce with the objects known.
Those who cut their ontology to suit their epis- temology will supply different accounts of number. For instance, formalists and intuitionists identify numbers with inscriptions and mental constructs, respectively. But these categories of objects cannot supply enough objects to be numbers. Further, num- bers look to be necessary existents whereas both inscriptions and mental constructs are contingent existents.
A more radical response to the epistemological
problems is to deny the existence of numbers. Given Quine's criterion, to deny the existence of numbers is to deny the literal truth of sentences purporting to quantify over numbers. On such a view, arithmetical sentences are useful fictions that make for smoother science but are, in principle, dispensable. This claim of dispensability must be justified by showing how scientific theories can be expressed without reference to numbers.
3. Respect for Ordinary Discourse
Quine's criterion tells us what a theory says there is. To tell what there is we must also know which theories are true. A wide range of methodological and evi- dential criteria have been proposed as guides to the truth of a theory. It is a vexed question whether these criteria will vindicate the theories implicit in ordinary discourse.
A semantics for natural language will inevitably commit the users of that language to various cat- egories of entity. For example, verbs of action might be best characterized as referring to events and modal operators best characterized as quantifiers over poss- ible worlds. Moreover, some have thought syntactic and semantic characteristics of language determine the nature of the entities referred to. For example, Frege took the incompleteness of predicates to indi- cate an incompleteness of the properties to which the predicates refer. Similarly, some have argued from the vagueness of language to the existence of vague objects in the world. But many metaphysicians have less respect for ordinary language, diagnosing the apparent ontological commitments of our everyday discourse as the result of distinctively human interests and limitations which should not be taken as a guide to what there is.
Bibliography
Quine W V O 1980 On what there is. In: From A Logical Point of View, 2nd edn, revised. Harvard University Press, Cambridge, MA
'Ordinary Language Philosophy' is the title sometimes given to the views developed at Oxford by J. L. Austin and those influenced by him, or associated with him, in the period 1936-60.
1. The Debt to J. L. Austin
Austin (1957) recommended English-speaking phil- osophers to study the meanings and uses of English words on the grounds that the ordinary language of
Ordinary Language Philosophy L. J. Cohen
Ordinary Language Philosophy
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