Saturday, September 6, 2008

objection to Swoyer

In the Swoyer paper, he describes a problem for abstract objects:
"Epistemology is the Achilles' heel of realism about abstracta. We are biological organisms thoroughly ensconced in the natural, spatiotemporal causal order. Abstract entities, by contrast, are atemporal, non-spatial, and causally inert, so they cannot affect our senses, our brains, or our instruments for measuring and detecting"
A couple paragraphs down he elaborates:
"Indeed, even if abstracta did exist, it is difficult to see how they could make any difference to our cognitive processes. Things would seem just the same whether they existed or not" P.27

I have two responses:

On page 24 he states:
"We can rarely explain much with the bald assertions that numbers exist or that properties exist. These claims are typically part of a longer story, a philosophical theory, that tells us something about what the relevant abstract entity is like. The theory also needs to explain how the entity is related to other things ... The account also needs to tell us how its abstracta are related to the phenomena around us that led us to postulate them in the first place"

Any theory worth its salt will have these components. This means that the abstracta are in fact related to the (observable) phenomena around us. If properties are posited to explain why certain things are similar to other things, then properties will have a special relationship with those things that the theory must elaborate on. Once it does, a very real tie is established between the abstracta and something observable. I'm betting that in most cases this can easily be exploited to shed light on the epistemic problem.
Consider properties. They don't cause anything. However, objects do instantiate properties. There are observable differences between things that instantiate some properties rather than others. We can come to know of these abstracta by observing such differences.
Consider numbers. They must be in some way related to collections of objects if we're to say there are a certain number of objects in a collection. Moreover, how many objects there are in a collection is an observable fact, even though the number itself is not. Given strict relationships between numbers, once we come to know of a few it's not hard to gain knowledge of the rest.
A side note about the second quote. He states that if abstracta didn't exist then things would seem exactly the same to us. This is far from obvious. For instance, if abstract objects called properties are in fact responsible for the differences between objects and the relationships between them, then if there were none then no objects would ever be related to have any properties. You can sure bet that if that was the world we were in, we'd be experiencing it a heck of a lot differently.

He actually describes an epistemic rout to abstracta in his paper. We argue for abstracta by considering the merits of theories which posit them. How is that not a good way to gain knowledge of them? Why doesn't that qualify? Why must we posit an entity with great explanitory value, and then explain how we could have gained knowledge of it in another way?


Wes McPherson said...

Hi Dan,

I've probably missed the entire point of your post, I must admit. But it brings to my mind a question, and perhaps this is what Swoyer is roughly hinting at.

We might have some observation data to support the existence of abstracta, or we might find that a certain theory gains incredible explanatory power through positing their existence. But is this existence 'realist' or 'instrumentalist'?

It seems we could consider a case like positing particles to explain certain observable facts. Certainly positing particles helps to give our science great explanatory power. But are particles honest-to-god real? Or are they just instrumentalist posits?

Certainly if I posit God in all his glory, I have a powerful explanatory tool. But should I? It seems that at least some things we posit we could do without, and we would not be able to tell the difference whether they were there or not if they were 'purely' theoretical and barely tied to observables.

If we just admit posits because of their explanatory power, perhaps we can make a case that we are limiting their existence to a framework because they are not honest-to-god real. They might, say, lack a narrowly defined physical existence, but exist as entities in some other sense.

Perhaps something like this is what Swoyer is hinting at?

Dan said...

Hi Wes,
I'm not sure how this instrumentalism is supposed to work. We posit entities for their explanitory power, but deny their existence? Or just deny their realist existence?

On a side note, I don't believe positing God has much explanitory power in any significant sense.

Wes McPherson said...

Hi Dan,

I think an instrumentalist would only have to claim that by saying that something exists, they are saying that it has a central role in scientific or inductive explanation, and that that central role makes it indispensable. It coheres into our web of belief, say. There is no need to talk about a 'full-blooded' physical existence for posited entities. An empiricist may even claim that the only thinks that exist are immediate experiences.

I am not supporting such a position, because I think the basic picture of instrumentalism and phenomenalism is false. But there are philosophers who posit a special kind of direct or immediate knowledge. Theoretical entities like molecules, atoms, particles and processes are beyond the scope of this special kind of knowledge and cannot be directly linked to 'sense-meanings' or ostensive definition.

A realist of course would disagree with the notion that something exists by virtue of having some explanatory power that makes it indispensable. But presumably they may not disagree that some levels of philosophy or science are more basic or better known and deserve a sort of first-class existence, and that some have a more derivative or theoretical sort of second-classe existence. Perhaps only some abstract or theoretical entities end up with full-blooded existence.

Swoyer's point is perhaps just that given the above, we have to understand what defines existence according to a particular understanding in philosophy or science. Perhaps abstract entities are objects of philosophy, or perhaps of science. Perhaps they exist by the definition of one interpretation of what it means to exist, but perhaps not by another interpretation. Much more needs to be clarified with our regards to our terminology.

I only mentioned God because it seems that someone could have a very simple ontology and a very simple model of the universe. God would be Nature or the One or whatever else, and play a fairly serious role in explanation. Such a model could be a perfectly coherent system which effectively explains our observations of the world. Alternatively we can consider more complex ontologies and models. God could be explained away. I think one could say that in principle we can consider a more complex ontology which excludes abstract entities. At least at a glance it seems we could make analogous moves with regards to abstract entities as we did with divine beings.

Dan said...

Hi Wes,
A lot of this seems to be the sort of thing that Ciann Dorr is talking about in his paper. I'll respond when I'm finished reading that.

Wes McPherson said...

Hi Dan,

I'm sorry if I have confused the two! They both seemed to be hinting at this, as I see it...