Much of the difficulty of the topic of the previous post simply results from the difficulty of understanding the idea of part and whole. In our original discussion of these concepts, I noted that in order to be a whole, a thing must be itself, but also in a certain way other things which it simply speaking is not.

There is a temptation to say that this is a contradiction: since we admit that the whole is not its part, it cannot be that part in any way, and therefore it cannot satisfy our definition of a whole. And thus it would be impossible to have a whole and parts.

Parmenides attempts to resolve this problem in a simplistic manner, namely by denying the reality of distinction. Since it is impossible for one thing to be distinct from another, it is impossible to for there to be many things which could be made into a whole. There is only one thing, and consequently no need to make anything out of parts.

A more sophisticated and more common solution is to admit the reality of distinction, but to continue to deny the possibility of forming wholes from parts. By confusing the idea of “fundamental” as the primary material cause with the idea of “fundamental” as most real, Sean Carroll accepts this solution.

Both proposed solutions are contrary to common sense, and both effectively deny the reality of all the things of our common experience. Parmenides makes this denial openly, Carroll by implication, although he at least wishes to avoid it.

There is an additional inconsistency in Carroll’s view insofar as we cannot avoid thinking of the universe as a kind of whole. In other words, just as Parmenides wished to say, “there is only one thing,” Carroll wishes to say, “there are only many things.” But this cannot be done: for there cannot be many things, unless those many are in some way one.

Alexander Pruss attempts to formulate a still more sophisticated solution, which to some extent we have already discussed:

Some people are attracted to nihilism about proper parthood: no entity has proper parts. I used to be rather attracted to that myself, but I am now finding that a different thesis fits better with my intuitions: no entity is (fully) grounded. Or to put it positively: only fundamental entities exist.

This has some of the same consequences that nihilism about proper parthood would. For instance, on nihilism about proper parthood, there are no artifacts, since if there were any, they’d have proper parts. But on nihilism about ontological grounding, we can also argue that there are no artifacts, since the existence of an artifact would be grounded in social and physical facts. Moreover, nihilism about ontological grounding implies nihilism about mereological sum: for the existence of a mereological sum would be grounded in the existence of its proper parts. However, nihilism about ontological grounding is compatible with some things having parts–but they have to be things that go beyond their parts, things whose existence is not grounded in the existence and relations of their parts.

Note that he states that he was formerly attracted to the view that “no entity has proper parts.” This would assert, like the views of Parmenides and Sean Carroll, that wholes and parts are impossible. Since this seems too opposed to common sense, he formulates a new view, where it is possible for a thing to have parts, but the thing must “go beyond” its parts in some way. The existence of the whole “is not grounded” in the existence and relations of its parts.

It is not clear to me precisely what he means by grounding here, and his position could be true, if this is understood in some ways, and not true, if it is understood in others. It could be taken in a fairly tautological sense: something with parts is real if it is really one thing, and not merely many things. But we could just as well say that many things cannot exist without being in some way one. And this does not seem to be Pruss’s intended meaning, since he denies the reality of artifacts, even in this text, which would not be necessary on this understanding.

In any case there does seem to be some remaining desire to deny in some way the possibility of whole and part, indicated for example in the statement that “only fundamental entities exist.” Of course if we understand “fundamental” to mean “real,” then the statement is that only real things exist, and this is obviously true. But like in the case of Carroll, it is evident that fundamental here is meant to refer in some way to what things are made from, namely to material causes. The difference is that rather than saying that the fundamental things are particles of some kind, Pruss would say that some fundamental things are particles, while others are human beings and so on.