Against Monism

According to Monism:

• (M) Necessarily if there are any concrete physical objects, then there is a concrete physical fundamental object (“a cosmos”) that has all concrete physical objects as metaphysically dependent parts.

Here an object is fundamental just in case it is not metaphysically dependent. But Monism is difficult to reconcile with the Intrinsicness of Fundamentality:

• (IF) Necessarily, if x is a fundamental object, then any exact duplicate of x is fundamental.

For simplicity, let’s call concrete physical objects just “objects”, and let’s only talk of the concrete physical aspects of worlds, ignoring any spiritual or abstract aspects.

Now consider a world w₁ that consists of a single simple object (say, a particle) α. Let w₂ be a world consisting of an exact duplicate α′ of α as well as of one or more other simple objects. Then by (M), α′ is not fundamental in w₂, since it is dependent on w₂’s cosmos (which is not just α′, since w₂ has some other simple objects). But α is the cosmos of w₁, and hence is fundamental, and thus by (IF), α′ is a duplicate of a fundamental object, and hence fundamental.

I can think of one way out of this argument for the defender of (M), and this is to deny the weak supplementation axiom of mereology and say that in w₁, there are two objects: α and a cosmos c₁ which has exactly one proper part, namely α. This allows the monist to deny that α is fundamental in w₁. Many people will find the idea that you could have an object with exactly one proper part absurd. I am not one of them in general, but even I find it problematic when the object and the proper part are both purely physical objects.

Still, let’s consider this view. We still have a problem. For in w₁, there is an object, namely c₁, that has α as its only proper part. Now, suppose a world w₃ that contains a duplicate c₁′ of c₁, and hence a duplicate α′ of α that is a part of c₁′, as well as one or more additional simples. Then c₁′ has only one simple as a proper part, and hence is not the cosmos of w₃, and thus is not fundamental by (M), which contradicts (IF).

So, we cannot have a world w₃ as described. Why not? I think the best story is that a cosmos is a unique kind of organic whole that encompasses all of reality, and that exists in every world which has a (concrete physical) object, and nothing but the cosmos can be a duplicate of the cosmos.

But this story violates the following plausible Distinctness of Very Differents principle:

• (DVD) If x and y are organic wholes made of radically different kinds of particles and have radically different shape and causal structure, then x ≠ y.

But now consider a world consisting of a cloud of photon-like particles arranged in a two-dimensional sheet, and a world consisting of a cloud of electron-like particles arranged in a seven-dimensional torus. The cosmoses of the two worlds are made of radically different kinds of particles and have radically different shape and causal structure, so they are not identical.