John Venn didn't name the diagram after himself. The Venn diagram was named such by American philosopher and pragmatist Clarence Irving Lewis in his 1918 book “A Survey of Symbolic Logic.”

Mark Perry, an economics and finance professor at University of Michigan-Flint and author of the Carpe Diem blog, is an AVID fan of Venn diagrams. He uses them regularly, and in many entertaining ways. His "intellectual consistency" diagrams are a running gag so he put together a few to celebrate Venn's birthday. Here are some fun (ok, also nerdy and possibly vexing) ones!

On protectionism.

On carbon footprints.

On the "wage gap."

See more Venn diagrams at Carpe Diem.