In the Critique of Pure Reason, Immanuel Kant has a chapter on the architectonic of pure reason. There he writes: Ich verstehe unter einer Architektonik die Kunst der Systeme. (By an architectonic I understand the art of systems.) Kant describes a whole built from an idea: Das Ganze ist also gegliedert (articulatio) und nicht gehäuft (coacervatio). (The whole is therefore articulated and not heaped up.) And he adds: Die Idee bedarf zur Ausführung ein Schema, the idea needs a schema for its execution.