Venn debuted his diagrams in 1880 as a method for visualizing contemporary advances in logic. They then found application in the closely related branch of math called set theory, which focuses on collections of objects. Venn diagrams typically consist of overlapping circles, with each representing some set of elements, (e.g., things that are cuddly or Broadway shows). The overlapping region between two circles contains elements that belong to both sets (e.g., “cats”). Much like in using scatter plots in statistics or drawing shapes in geometry, seeing one’s problem often clarifies it.