When we regard the mother as a unit, it is we who have distinguished her from the womb that is society. We can do the same for the child. Now suppose we regard the mother as 1: does she remain 1 when she eats, or when she excretes, or when she loses a limb? Does she have a distinct, imperishable essence that is 1?

We may call the universe 1, or the galaxy, or the stellar system, or the planet, or the ecosystem, or the organism, or the organ, or the cell, or the molecule, or the quantum. It's completely arbitrary.

I think we can only say, rationally, not empirically, that the All is 1, and that it is the only thing of its kind, so there is no 1+1. Within the All, we may define units, but we can never define identical units, so there is no 1+1 there, either.