Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

This comic is a philosophy joke centered on Immanuel Kant's concept of "the thing-in-itself" (das Ding an sich). The comic shows Kant arguing with his girlfriend. He insists something is "an important epistemological concept," to which she responds, "Then take off your pants and let me see it." A distraught Kant replies, "Why you gotta ruin everything for me?" The caption below reads: "Immanuel Kant hates when his girlfriend calls his penis 'the thing-in-itself.'"

In Kant's philosophy, "the thing-in-itself" (or noumenon) refers to the true nature of reality as it exists independently of our perception -- something we can never directly access or experience, only infer. The joke works on two levels: first, it's a straightforward pun, since "the thing-in-itself" sounds like a euphemism for genitalia. Second, there's a deeper philosophical humor in the idea that Kant's girlfriend is undermining his grand epistemological theory by reducing it to a crude double entendre, making it impossible for him to discuss the concept with a straight face ever again.

The votey panel shows two people watching the comic unfold, with one saying "It's a philosophy joke" and the other countering "It's a dick joke." This meta-commentary acknowledges the dual nature of the humor and the tension between highbrow philosophical reference and lowbrow body humor -- which is itself a very SMBC thing to do.