The Traité de Lutherie is a practical and theoretical guide designed to provide instruction in measuring and drawing techniques. Although its primary subject is instrument making, it sheds light on an enigmatic aspect of craftsmanship which involves extracting proportions and measurements from the rotation of regular polyhedra.
Those who are intrigued to find the ramifications of neo-Pythagorean thought still at work will find in this section reflections on some of the specific themes which underpin the book.

The rotation of the square is the image most frequently
associated with the production of form. It illustrates the proportions of the harmonic section.
(Traité de Lutherie, pp. 32-37)