Weyl expanded on ideas he published in a 1927 paper,[1] basing the text on lectures he gave at ETH Zurich during the 1927–28 academic year.

[6] John Archibald Wheeler wrote of learning quantum mechanics from Weyl's book, "His style is that of a smiling figure on horseback, cutting a clean way through, on a beautiful path, with a swift bright sword.

"[8] The book was one of the first works to give a quantitative statement of the uncertainty principle, which Werner Heisenberg had previously introduced in a less precise way.

[8][15][16] Weyl noted that Paul Dirac's relativistic quantum mechanics implied that the electron should have a positively charged anti-particle.

Weyl wrote, "I fear that the clouds hanging over this part of the subject will roll together to form a new crisis in quantum physics."