 One may dispute the very meaningfulness of claims of this kind, concerning the world as a whole: something that, to speak Kantian, is never given to us in experience. Floridi 2009 has argued against such digital ontology, not by defending a continuous picture of reality, but by arguing that the world is not the right kind of thing to which such notions as discreteness and continuity can meaningfully apply. These concern rather, in Kantian fashion, our ways of modelling reality, or “modes of presentation of being”. If one, on the contrary, thinks that there must be a fact of the matter about the discrete vs. continuous nature of the world (as argued in Berto &amp; Tagliabue 2014, on the basis of considerations from cardinality and general mereology [see entry on  mereology]),  then the next issue is: what does (the philosophy of) fundamental physics have to say about this? It is fair to claim that the issue is open. Scholars such as Nobel prize winner ’t Hooft (1997) seriously explore discretist views, and approaches based on so-called causal set theory (see Dowker 2003; Malament 2006) take the geometry of real-world spacetime as such that at the Planck length (\(10^{-33}\) cm) it is discrete. Cognate strategies take spacetime as made of polysimplexes, usually polydimensional counterparts of tetrahedra (see Ambjorn et al. 2004) ; adding the claim that such polysimplexes compute functions takes us already in the vicinity of CA. Other scholars, instead, are against the idea of a digital world. Deutsch (2005) and Hardy (2005) reject the view that quantum probabilities and quantum computing vindicate a discrete structure of space-time, and claim that quantum mechanics complies with the idea that the world is continuous even more than classical physics. While we are, thus, in the realm of speculation, we can nevertheless single out two main reasons to investigate the provocative claim that the world is a discrete CA. First, the arguments put forward to support the view may be philosophically interesting in themselves. Second, the ontological structure of a CA-world can be fruitfully compared to existing metaphysical accounts. Let us take each point in turn. 