La psiche
A 1651 Italian treatise on the soul, printed in Bologna by Carlo Zenero and held by the University of Toronto's Fisher Library, written for scholars and students of philosophy. Its pictures are plain geometric diagrams in black line on pale laid paper: triangles, arcs, and a stepped ladder of numbered horizontal bars, with letter labels at each point. A designer could take from them a spare, instructional vocabulary of labelled construction lines, compass arcs, and numbered tiers for minimalist diagrams.
