Medicina mentis : sive, Artis inveniendi praecepta generalia
Medicina mentis is a 1695 Latin treatise on logic and the theory of knowledge by Ehrenfried Walther von Tschirnhaus, printed in Leipzig by J. Thomas Fritsch for scholars and students. Its pictures are small geometric diagrams on laid paper: lettered circles, triangles, rectangles and dotted construction lines labelled A to H, which a designer could borrow as clean, schematic figures for technical or educational layouts.
