  Interestingly, one of the debates that has arisen recently surrounding Marchia’s scientific ideas concerns his concept of natural causation and predictability. In giving an analysis similar to the one above, one scholar remarked that “Marchia in essence is laying down one of the bases of modern science, at least before Heisenberg: predictability is theoretically obtainable in natural systems because natural causes are finite and act necessarily” (Marchia 2000, 22; Schabel 2000, 196–7). A second scholar replied that Marchia is not a natural determinist, that for him, while “generally it’s possible to achieve merely the habit of foreseeing the development of causal chains, … physical events happen because causes and effects have dispositiones or aptitudines that make more probable some chains than different ones.” According to this response, Marchia was more in line with “Heisenberg’s principle of indetermination” than with post-Galilean physics (Zanin 2006a). It seems clear, however, that Marchia’s analysis of dispositiones and aptitudines in this context is focused entirely on the problem of knowing causes that are fully contingent in themselves, that is, human free will, as outlined above in the section on  Philosophical Theology.  By Marchia’s time, treatments of divine foreknowledge of future contingents, where Marchia’s discussion occurs, had become almost exclusively concerned with the reconciliation of human free will and divine omniscience. Thus Marchia explains that the seemingly contingent effects of the natural world are not the issue here, since they are not really contingent at all, but necessary, given God’s general influence and understanding all natural causes taken together. Outside of human and divine free will, there are no sources of contingency. Indeed, the only reason the natural world can be called contingent at all is because God acts freely and contingently in the world as creator and sustainer, not because there is any real contingency in natural causation: