 It is important to contrast Pascal’s argument with various putative ‘proofs’ of the existence of God that had come before it. Anselm’s ontological argument, Aquinas’ ‘five ways’, Descartes’ ontological and cosmological arguments, and so on, purport to prove that God exists. Pascal is apparently unimpressed by such attempted justifications of theism: “Endeavour … to convince yourself, not by increase of proofs of God…” Indeed, he insists that “we do not know if He is …”. Pascal’s project, then, is radically different. He aims to show that we ought to believe in God, rather than that God exists. And he seeks to provide prudential reasons rather than evidential reasons for believing in God. To put it simply, we should wager that God exists because it is the best bet. Ryan 1994 finds precursors to this line of reasoning in the writings of Plato, Arnobius, Lactantius, and others; we might add Ghazali to his list—see Palacios 1920. Franklin 2018 presents striking parallels to Pascal’s Wager by Sirmond and Chillingworth from 1637 and 1638 respectively, thus predating Pascal by a few years. But what is distinctive is Pascal’s explicitly decision-theoretic formulation of the reasoning. In fact, Hacking 1975 describes the Wager as “the first well-understood contribution to decision theory” (viii). Thus, we should pause briefly to review some of the basics of that theory.