Predicates and Properties

We are warming up to an examination of deflationary theories of truth according to which truth is either not a property or not a metaphysically substantive property.  (I oppose deflationary theories of truth just as I oppose deflationary theories of existence.) But first some clarification of 'predicate' and 'property.'

1. I begin by resisting the traditional conflation of predicates and properties, a conflation in evidence when we hear a philosopher claim that "existence is not a predicate."  That claim makes no sense unless a predicate is a property.  After all, 'existence,' as an abstract substantive, is not grammattically tuited to occupy predicate position.  If, however, a predicate is a bit of language used to express a property, then the claim should be that " '. . . exists' is not a predicate."  That's in order, as is "Existence is not a property."  As expressing properties, predicates are distinct from properties.  Predicates are linguistic while properties are extralinguistic.

To be a bit more precise, predicates (whether types or tokens) are tied to particular languages whereas the properties they express are not so tied.  Thus schwarz is tied to German in the way black is tied to English, but the property of being black is tied to neither.  Equally, the property of being disyllabic is tied to no one language even though it is a property that only linguistic items can have.  Thus 'Boston' but not Boston is disyllabic.

2. Some of you will question whether there are properties distinct from predicates.  Question away.  But just realize that in order to raise this very question you must first have distinguished predicates and properties.  You must already have made the distinction 'at the level of intension' if not 'at the level of extension.'  For you cannot maintain that there are no properties distinct from predicates unless you understand the term 'property' just as you cannot maintain that there are no unicorns distinct from horses unless you understand the term 'unicorn.'

3. By my lights, you are a very foolish philosopher if you deny properties, but not if you deny universals.  If you deny universals you are merely mistaken.  So let's be clear that 'property' and 'universal' are not to be used interchangeably.  It is a substantive question whether properties are universals or particulars (as trope theorists maintain).  Universals I define as repeatable entities, particulars as unrepeatable entities.

4. The predicate/property distinction under our belts, we need to note three views on their relation.

5. One view is that  no predicate expresses a property.  I rejected this view in #3.  To put it bluntly, there is a real world out there, and the things in it have properties whether or not there are any languages and language-users. Some of our predicates succeed more or less in expressing some of these properties.

6. A second view is that every predicate expresses or denotes a property.  The idea is that for every predicate 'P' there is a property P corresponding to 'P.'  But then, given that 'exists' and 'true' are predicates, it would follow straightaway that existence and truth are properties.  And that seems too easy.  Deflationists, after all, deny for reasons that cannot simply be dismissed that truth is a property.  They cannot be refuted by pointing out that 'true' is a predicate of English.  The following equivalence is undeniable but also not formulable unless 'true'  is a predicate:

'Grass is green' is true iff grass is green.

The deflationist will take an equivalence like this to show that 'true' is a dispensable predicate and therefore one that does not pick out a property.  (On Quine's disquotationalism, for example, 'is true' is a device of disquotation: it merely undoes the semantic ascent displayed on the LHS of the biconditional.)  We should therefore be uneasy about the view that every predicate expresses or denotes a property.  The existence of a predicate does not show the existence of a corresponding property.  A predicate need not predicate a property.  It should not be a matter of terminological fallout that wherever there is a predicate there is a property.

7.  Determined to maintain  that every predicate expresses or denotes a property, a deflationist  could of course hold that existence and truth are properties, but not metaphysically substantive properties.  A deflationist could argue like this:

Every predicate expresses a property

'True' is a predicate

Ergo: Truth is a property, but not a substantive one.

But he could also argue like this:

Every genuine predicate expresses a substantive property

Truth is not a substantive property

Ergo: 'True' is not a genuine predicate.

8.  A third view about the predicate-property relation has it that some predicates pick out properties and some don't.  I suggest this is how we should use 'predicate.'  It then becomes a matter of investigation, not of terminology, whether or not there is a property for a given predicate.