What is a material being? Suggestion:
- x is material if and only if x is in space.
A minor problem: The philosophical tradition has it that materiality is some kind of a negative status. But (1) makes materiality be a positive status. A more serious problem: God is omnipresent, so (1) makes God material. Revision:
- x is material if and only if x occupies a proper part of space.
This takes care of the case of God and shows how materiality is a limitation on omnipresence. But imagine a world all of whose space is filled by a walnut. Surely, the walnut would still be material. So:
- x is material if and only if possibly x occupies a proper part of space.
This is better. Whether it is adequate will depend on one's intuitions about things like the electromagnetic field. Suppose one thinks both that (a) the electromagnetic field is not a material being and (b) God could miraculusly make it occupy a proper part of space. (I assume that normally it occupies all of space, even the places where its value is zero.) Then (3) is inadequate. I am happy to count the electromagnetic field as material myself. But if you're not, then:
- x is material if and only if necessarily it is abnormal for x to occupy only a proper part of space.
