“He wished Kant were alive. Kant would have appreciated it.

That master diamond cutter.”

— Robert M. Pirsig, *Zen and the Art of Motorcycle Maintenance* , Part III.

*Kant’s* “category theory” —

“In the Transcendental Analytic, Kant deduces the table of twelve categories, or pure concepts of the understanding….
The categories must be ‘schematized’ because their non-empirical origin in pure understanding prevents their having the sort of sensible content that would connect them immediately to the objects of experience; transcendental schemata are mediating representations that are meant to establish the connection between pure concepts and appearances in a rule-governed way. Mathematical concepts are discussed in this context since they are unique in being pure but also sensible concepts: they are pure because they are strictly — Shabel, Lisa, “Kant’s Philosophy of Mathematics”, |

See also The Diamond Theorem and Octad.us.