 If we substitute “space-time points” with “cells”, HS gets very close to a CA ontology: cells are arranged in a lattice, have various spatiotemporal relations to one another (e.g., being a neighborhood of), and have monadic properties (states) which can be considered perfectly natural, i.e., the basic properties out of which any other can be construed. A CA universe is thus a prima facie abstract model of Lewis’ HS and can be fruitfully used to illustrate Lewis’ original point, which was a reductionist one: 