An unusually clear metaphysical conviction that nature ought to use the beautiful geometrical possibilities of pure infinitesimal geometry prevented Weyl from abandoning his idea

As London (1927, 376–377) remarks, one must admire Weyl’s immense courage in developing his gauge invariant interpretation of electromagnetism and holding on to it on the mere basis of purely formal considerations. London observes that the principle of equivalence of inertial and gravitational mass, which prompted Einstein to provide a geometrical interpretation of gravity, was at least a physical fact underlying gravitational theory. In contrast, an analogous fact was not known in the th