Kant wrote The Critique of Pure Reason largely as a response to Hume's skepticism. You can see more about that on the notes for comic 39, 'The Fresh Prince of Philosophy'.

Hume jokes are all the same (and super easy to think of), they are either about the Is-ought problem or The Problem of Induction. Hume was also famous for saying that reason is (and should be) a "slave of the passions", so I mixed it up a bit. You have to believe me, I am trying to come up with a bundle theory joke, but it isn't as easy as it sounds.

Bertrand Russell was pretty much as close to a Vulcan as we ever got. Although, actually, maybe Descartes would have been better considering the other characters. Oh well. Bertrand Russell also looks like a Vulcan, so there's that.

Star Trek was a popular sci-fi television and movie series, best known for being not as good as Star Wars.