Grothendieck's "Hexenküche" (German for "Witches' Kitchen") is a famous 1971 satirical doodle and handwritten note by mathematician Alexander Grothendieck. After spending two hours explaining the Riemann–Roch theorem, he reduced it to a commutative diagram, devils and flames included, then warned that our drive for knowledge and discovery was becoming a "logical delirium detached from life."
