“Paid to Touch Your Junk” Venn Diagram Ontologically Deconstructed

This past week, there’s been a Venn diagram making its way around the Internet, the punchline of which is that doctors, prostitutes, and TSA agents all intersect in that they “get paid to touch your junk.” Andrew Plotkin (a.k.a. Zarf), takes issue with the original diagram’s use of Venn notation — since really, “all three circles are people who get paid to touch your junk,” and thus the intersection at the center of the original diagram should not technically be an intersection at all, but a larger group that encompasses all three professions. After thinking things through a little and coming up with even more complicated diagrams, Plotkin offers the above diagram as a correction:

The insight, of course, is that we’re no longer mapping people; we’re mapping properties that people have. You can think of De Morgan’s law. The union of two properties is the intersection of the sets of people who have those properties. (And vice versa.)

Reasoning about properties is much more interesting than reasoning about things.

Interestingly, the Internet famous and somewhat sacrilegious Venn diagram comparing Jesus to movie monsters is a well-formed Venn diagram, since the large circles (“resurrected from the dead”; “convert as many mindless followers as possible”; “local townspeople fear and revere him”) indeed constitute properties, whereas the areas of intersection are correctly used to denote sets of “people,” broadly defined.

(Andrew Plotkin via Hacker News)