2008b) “How Weyl stumbled across electricity while pursuing mathematical justice” Studies in history and philosophy of modern physics, doi:10.1016/j.shpsb.2008.06.003

It is argued that Weyl’s theory of gravitation and electricity came out of ‘mathematical justice’: out of the equal rights direction and length. Such mathematical justice was manifestly at work in the context of discovery, and is enough (together with a couple of simple and natural operations) to derive all of source-free electromagnetism. Weyl’s repeated references to coordinates and gauge are taken to express equal treatment of direction and length.