He was a frequent visitor to the Frankfurt Mathematics Seminar in the 1920s and 30s, where his friend Hellinger worked from 1914, and there the history of mathematics played a large role. Toeplitz believed:
Siya ay isang madalas na bisita sa Frankfurt Mathematics pantas-aral sa 1920s at 30s, na kung saan ang kanyang mga kaibigan Hellinger nagtrabaho mula 1914, at doon ang kasaysayan ng matematika nilalaro ng isang malaking papel na ginagampanan. Toeplitz sumampalataya: