Monday, September 11, 2017

Reductive accounts of matter

I’ve toyed with identifying materiality with spatiality (much as Descartes did). But here’s another very different reductive idea. Maybe to be material is to have energy. Energy on this view is a physical property, maybe a functional one and maybe a primitive one.

If this view is right, then one might have worlds where there are extended objects in space, but where there is no matter because the physics of these objects is one that doesn’t have room or need for energy.

Note that the sense of “matter” involved here is one on which fields, like the electromagnetic one, are material. I think that in the philosophical usage of “material” and “matter”, this is the right answer. If it turned out that our minds were identical with the electromagnetic fields in our brains, that would surely be a vindication of materialism rather than of dualism.

Now, here’s something I’m worrying about when I think about matter, at least after my rejection of Aristotelian matter. There seem to be multiple properties that are co-extensive with materiality in our world:

  • spatiality

  • energy

  • subjection to the laws of physics (and here there are two variants: subjection to our laws of physics, and subjection to some laws of physics or other; the latter might be circular, though, because maybe “physics” is what governs matter?).

Identifying matter with one or more of them yields a different concept of materiality, with different answers to modal questions. And now I wonder if the question of what matter is is a substantive one or a merely verbal one? On the Aristotelian picture, it was clearly a substantive question. But apart from that picture, it’s looking more and more like a merely verbal question to me.


Speed Limit Forty said...

I wonder if the first two are coextensive with the third. Say I have a restaurant and I decide to change locations from where it is to the other side of town. I sign a legal document that closes the current location and opens the new location immediately upon my signing. Didn't the restaurant move faster than the speed of light? Is the restaurant not material?

Hawthorne has a paper "Motion and Plenitude" where he gives several examples of objects plenitude generates which seem to be both material and fail to satisfy the laws of physics. Though some of the examples (like the restaurant) don't seem to rely on some of the weirder objects that come with plenitudinous ontologies.

Alexander R Pruss said...

Good question. I would say that a lesson learned is that the laws of physics do not say that objects can't move faster than light. Rather, they say that physically fundamental objects can't move faster than light, which has implications for objects like restaurants that aren't physically fundamental. The latter are governed by the laws of physics, but in a complicated way. Consider, for instance, the stream of water from a faucet. The stream, in seeming violation of the laws of gravity, is staying put. But of course the stream is behaving in accordance with the laws of physics: the water it's made of is falling, and it has the sort of stability that physics predicts for streams.