If you can excuse the flippancy, one might define category theory as algebra that benefits from two-dimensional equations.

To be more serious, sketches in category theory, or the various classes of visual inference in logic, such as Peirce's existential graphs, show that visually represented reasoning can be quite as rigorous as textually based reasoning.

If you can excuse the flippancy, one might define category theory as algebra that benefits from two-dimensional equations.

To be more serious, sketches in category theory, or the various classes of visual inference in logic, such as Peirce's existential graphs, show that visually represented reasoning can be quite as rigorous as textually represented reasoning.