The Commens Dictionary
Quote from ‘Logical Diagram (or Graph)’
Logical Diagram (or Graph): Ger. Logische Figur; Fr. Diagramme logique; Ital. diagramma logico. A diagram composed of dots, lines, &c., in which logical relations are signified by such spatial relations that the necessary consequences of these logical relations are at the same time signified, or can, at least, be made evident by transforming the diagram in certain ways which conventional ‘rules’ permit.