What 1886 Lewis Carroll book uses coins on a board to teach logic?

Lewis Carroll’s 1886 book The Game of Logic uses coins on a board to teach the fundamentals of logic.

Carroll, whose real name was Charles Lutwidge Dodgson, was a mathematician and lecturer in mathematics at Christ Church, Oxford. He presented logical propositions as a playful board game, making abstract ideas about categories, syllogisms, and inference easier to visualize.

The game divides a logical universe into regions representing combinations of properties. Players place coins in those regions to show whether objects satisfying particular conditions exist or do not exist. Carroll’s example involves fresh and sweet cakes, with red and gray coins representing presence and absence.

The title is sometimes confused with Symbolic Logic, the more formal work Carroll published later, in 1897. Pillow Problems is a separate collection of mathematical puzzles, while A Tangled Tale presents mathematical problems through linked stories. The Game of Logic stands out because it turns logical classification into a physical tabletop exercise.