Greg you goddamn arrogant moron, the ontological argument is a basic shorthand for a common religious argument that you saw back when you were a whiny atheist preteen, remember? You would have known this if you'd bothered to just google "ontological argument", you absolute hack.
I should start counting the comics that just have these two characters walking and saying the end of a conversation we didn't get to see. (See: #1315, #1345) It's like hearing fifteen second excepts from a bad comedy podcast.
Speaking of comedy podcasts, I recently found the The Worst Idea Of All Time Podcast podcast, which is kinda like this blog, except instead of XKCD it's Grown Ups 2, and instead of me it's two actual established comedians. Go listen to it! It's good, and not bad, as the segue into my mentioning it might have you believe!
Have you ever walked into a conversation just as someone gets to the punchline of a story, and everyone laughs but you?
VR Simulation for those who haven't: "...and it turns out my underwear had just bunched up." / *laughter*
That's also what this comic reminds me of. They know what the hell they're talking about, we don't. Especially not when Randy calls it "The Ontological Argument".
I don't understand why he doesn't just add a panel or two of expository dialogue before dropping the punchline, like in #1404.