The errors of Feynman and Hibbs

In 1965, Richard Feynman and his former graduate student Albert Hibbs published a textbook on Quantum Mechanics and Path Integrals. This text — based on Feynman’s teaching of graduate-level quantum mechanics courses at CalTech — is full of remarkable insight and excruciating errors. The errors have been corrected through an emended edition. This article investigates the source of those errors.