Wednesday, April 13, 2016

Two conceptions of matter

The philosophical tradition contains two conceptions of matter. One kind, associated with Descartes, connects matter with space: matter is what is responsible for spatial properties like extension or location. The other, associated with Aristotle, connects matter with passivity: matter is what makes an entity have a propensity to be the patient of causal influences. The spatial conception of matter has been the more popular one in recent times. But here is a reason not to go for the spatial conception of matter. The concept of materiality seems fairly close to the fundamental level. But it may well turn out--string theory is said to push in that direction--that at the fundamental level there is no such thing as space or time or spacetime. If that is a serious epistemic possibility, it would be good to do more work on the Aristotelian option.

4 comments:

Heath White said...

What about the modern physicists' conception of matter as what has mass? (Or at least, so I understand.) E.g. black holes have mass but do not properly speaking take up space.

Alexander R Pruss said...

Unless one includes relativistic mass (i.e. the mass coming from energy), that will exclude photons and gluons. But it doesn't seem to me to be right that some particles but not others be matter.

Maybe, then, matter is what has energy?

Here is a worry about using either mass or energy as the definition. These seem to be natural kinds tightly tied to the actual world's physics. If so, then if the laws were different, there would be no matter. But it seems that matter could be governed by other laws.

Maybe, though, there is some vague functional account of mass or energy that works across a spectrum of laws?

Alexander R Pruss said...

Unless one includes relativistic mass (i.e. the mass coming from energy), that will exclude photons and gluons. But it doesn't seem to me to be right that some particles but not others be matter.

Maybe, then, matter is what has energy?

Here is a worry about using either mass or energy as the definition. These seem to be natural kinds tightly tied to the actual world's physics. If so, then if the laws were different, there would be no matter. But it seems that matter could be governed by other laws.

Maybe, though, there is some vague functional account of mass or energy that works across a spectrum of laws?

Jakub Moravčík said...

If essentiality od matter is passivity, then intellectus possibilis would ve material ...