Pascal's Wager and Probability Aptitude

It's hard not to get exposed to Pascal's wager at some point in your life. It's one of those things that's so offensive to clear thinking that it practically has noticeable stench to it. It's pretty much a given that any one in this day and age who presents it as a valid argument for belief is a serious crack pot and/or hasn't really thought about it for more than a few minutes.

But then, how did the great man Pascal come to make such an argument. I mean the guy has a triangle named after him and everything. He's got to have been a sharp cookie. But of course after a while you stop being surprised when otherwise smart people have these huge blind spots with respect to religion. That's just one of those weird failure modes of the mind.

But what if the explanation was simpler? What if Pascal just simply didn't understand probability theory? Surprisingly this actually seems to be the case.

Here is a video of Keith Devlin (who I normally find pretty objectionable as the NPR "Math Guy") giving a talk that among other things goes over the inception of probability theory. And who should be at attendance at the birth of this topic? Our friend Pascal. And who should be showing a complete confusion at the topic? I think you can guess.

Pascal, Fermat and Probability