This chapter clarifies the philosophic dimension of Montesquieu’s essay on Rome, which comes to sight when, in chapter 18, Montesquieu makes explicit that he is presenting here a preeminent case study vindicating the contention that “it is not Fortune that dominates the World”; there are “general causes, some moral, some physical, which operate,” and “all the accidents are subject to these causes.” This foreshadows the claim with which Montesquieu opens his Spirit of the Laws: “I have posed the principles, and I have seen the particular cases unfold therefrom as if by themselves; the histories of all the nations are nothing but the consequences.” These statements signal the emergence of the modern philosophy of history, as a major component of Enlightenment rationalism’s most ambitious project and hope: to show that human reason can provide a system of universal causal explanation that will leave no room for plausible evidence of governance by supra- and contra-rational providential and legislative divinity (which is profoundly opposed not only to revealed religion but to ancient political rationalism.)