No one was more familiar with the impact of Einstee British confirmed Einstein's result during the solar eclipse of 19in's general theory of relativity on mathematics and mathematicians than Hermann Weyl, who threw himself headlong into this new field shortly after the appearance of Einstein's classic paper (Einstein 1916). In the summer semester of 1917 Weyl taught a 3 h course at the ETH in Zurich on "Raum, Zeit, Materie." The idea to publish a book based on these lectures came from Einstein's close friend, Michele Besso (CPAE 8B 1998b, 663). One year later, the first edition of Weyl's classic Raum-Zeit-Materie (Weyl 1918) was already in print.