 Without any assumption about your probability assignment to God’s existence, the argument is invalid. Rationality does not require you to wager for God if you assign probability 0 to God existing, as a strict atheist might. And Pascal does not explicitly rule this possibility out until a later passage, when he assumes that you assign positive probability to God’s existence; yet this argument is presented as if it is self-contained. His claim that “[r]eason can decide nothing here” may suggest that Pascal regards this as a decision under uncertainty, which is to assume that you do not assign probability at all to God’s existence. If that is a further premise, then the argument is apparently valid; but that premise contradicts his subsequent assumption that you assign positive probability. See McClennen for a reading of this argument as a decision under uncertainty.