 The contentious elements of Bayle’s doctrine begin to surface when the debate then turns to a posteriori reasons; that is, once the question shifts away from the beauty of the theory to its ability to account for the observable phenomena. In this debate Melissus fares worse than his interlocutor, since human reason finds “the manner in which evil was introduced under the empire of a sovereign being, infinitely good, infinitely holy, and infinitely powerful … not only inexplicable, but even incomprehensible; and everything that is opposed to the reasons why this being permitted evil is more agreeable to the natural light and to the ideas of order than these reasons are” (Dictionnaire, “Pauliciens,” rem. E). Simplicity and elegance are now on the side of Zoroaster (and the Manichean tradition that followed him, if Bayle’s history is correct), for whom all the good in the world is traceable to a perfectly benevolent deity, while all the evil is the effect of his malevolent enemy. Therefore, whereas a priori reason and Christian Scripture point toward monotheism (Bayle’s first principle), a posteriori reason raises perpetual difficulties for this picture in light of the way the world actually is (Bayle’s second principle). 