A problem for Van Inwagen's life condition for composition

Van Inwagen thinks that a plurality of xs composes something if and only if either there is only one thing among the xs or the xs have a life together.

He also agrees that the fundamental particles making up a cell in a multicellural organism have a life together, and so there are cells.

Here is a problem. The following seem true:

1. It is possible to have two overlapping cells in a multicellular organism neither of which is a part of the other.

2. The cells of a multicellular organism together with any intracellular fundamental particles have a life together.

Why think (1)? Because, first, conjoint twins show that multicellular organisms can have “proper overlap”: i.e., they have a part in common but neither is a part of the other, and it seems hard to deny that cells, too, could in principle be like that. Second, it seems plausible that mid-way through a process of mitosis we have two cells that properly overlap.

It seems hard to deny (2), assuming there are cells.

But now consider a multicellular organism which happens to have two overlapping cells. Its cells, together with any intracellular fundamental particles, have a life together. Hence, by van Inwagen’s famous account of composition, the cells and the intracellular fundamental particles compose something. But van Inwagen’s definition of composition includes a no-overlap condition: if the xs compose y, no two xs overlap. And yet in our case we have life and overlap.

What should van Inwagen do? One move would be to weaken the Special Composition Question. Instead of asking when the xs compose something, he could ask when non-overlapping xs compose something. But that makes his view rather less informative than we might think, if overlap between cells is fairly common. Presumably in a body of my size, at any given time, mitosis is occuring in a number of cells (I haven’t done the math, but it seems likely).