Thursday, January 16, 2014


One of the fundamental concepts of bundle theory is a coinstantiation relation between properties. Interestingly, it may be possible to reduce coinstantiation to instantiation and entailment. Specifically, a bundle theorist may say that the Ps (some plurality of properties) are coinstantiated if and only if there is a property Q such that (a) Q entails each of the Ps and (b) Q is instantiated.


Jonathan D. Jacobs said...

Couldn't it be just the Ps? That is, couldn't the bundle theorist make it as part of the identity condition of the Ps that they are co-instantiated? You'd get some interesting issues with persistence, but where we would normally say that some property, Q, persists and the substance that has Q changes, we could either say that an exactly similar trope, Q2, replaces the previous trope, Q1, or be perdurantists about substance.

In this way, they could reduce instantiation to existence and entailment.

Alexander R Pruss said...


I don't understand your proposal. Could *what* be just the Ps?

Jonathan D. Jacobs said...

"It" was meant to refer to "the reduction base". So the idea was this:

Suppose P, Q, and R are coinstantiated. What does that come to, metaphysically speaking? It comes to P, Q, and R each being essentially such that, if it is instantiated, so are the others. So P is essentially such that, if P exists, it is coinstantiated with Q and R. And Q and R are like that, mutatis mutandis.

The Ps are coinstantiated iff one of them exists and the existence of any one entails that all the others are instantiated.

It's not terribly different than what you proposed, but it seemed as if the Q in your analysis was something other than the Ps. So I asked, if it works for Q, can't it work just with the Ps?

Alexander R Pruss said...

We may have a misunderstanding of "coinstantiation". Intuitively, "P and Q are coinstantiated" means that there exists an x such that x instantiates P and x instantiates Q. (I say "intuitively", because of course the bundle theorist can't say this.) Are you thinking of a different sense?

Alexander R Pruss said...

I just noticed that my punctuation was misleading, and I disambiguated the post. Maybe this will help.

Brian Cutter said...

This would seem to have the consequence that you'll need more properties in your ontology than the "classical" bundle theorist (i.e. the bundle theorist whose ideology includes a primitive predicate for coinstantiation). Specifically, where the classical bundle theorist accepts fundamental properties F1, F2,... Fn, this "revisionary" bundle theory must accept an additional property for each coinstantiable subset of {F1,...Fn}. Also, there does not seem to be any ideological simplification achieved by the revisionary view. The revisionary view takes "instantiates" as primitive, but can't we define "instantiates" in terms of "coinstantiates"? I.e.: F is instantiated iff F is coinstantiated.? ("is coinstantiated" is a variably polyadic predicate; here the adicity is 1.) If so, then this looks like trading one primitive for another.

I suppose one might try to argue that a theory with variably polyadic predicates is (ceteris paribus) more ideologically complex than one without any.

Alexander R Pruss said...


The last line is what I was thinking.