What fallacy in Pascal's Wager allows replacing God with the devil?

Question

I wanted to know the name of the fallacy or fallacies the Pascal's Wager in the sense that it can be applied to motivate one's belief in many things. A similar argument to the original Wager can be used to say that it is prudent is to believe in the devil (of course not in conjunction with a Christian God), or that black magic works, or really any unlikely belief that might have some potential benefit. When it justifies many cases does it not weaken the argument in case of God? If so what fallacy is this?

Answer 1

I'm not sure if there's an official name for the fallacy you're after here, but we could call it the "proves-too-much" fallacy. A common way to object to an argument is to argue that its reasoning is bad because it "proves too much" because it can be used to prove all kinds of unsavory things. So yeah, if Pascal's prudential/pragmatic justification for theistic belief can be used to justify all kinds of wacky, unjustified beliefs, then we should definitely be skeptical that Pascal offered real justification for theistic belief.