Within ten years of the execution of Louis XVI two general and opposed features of the Old Regime, Catholic Christianity and Enlightenment rationality, were globally idealized by two authors—both of them former aristocrats— François-René de Chateaubriand (1768–1848) and Antoine-Louis-Claude Destutt de Tracy (1754–1836). No two participants in the complex discussion of religion and secularism that took place at the highest levels of government and Parisian intellectual life at the end of the First Republic and during the Napoleonic regime better represented on the one hand unconditional nostalgia for Catholicism, and on the other uncompromising intellectual pursuit of the secular scientific ideal. Though it has become customary to oppose the Neo-Christian intellectuals Chateaubriand, De Maistre, De Bonald, and Ballanche, to the Idéologues Destutt de Tracy, Cabanis, Maine de Biran, and others, I believe that this opposition can be clarified if the extremes represented by Chateaubriand and De Tracy are better defined. In other words, a clear definition of the personal metaphysics—thoughts and feelings—of Chateaubriand and De Tracy should establish the polarities of intellectual temperament that characterized the Napoleonic era.