Nagel was born in Nové Mesto nad Váhom (now in Slovakia, then Vágújhely and part of the Austro-Hungarian Empire) to Jewish parents.

He received a BSc from the City College of New York in 1923, and earned his PhD from Columbia University in 1931,[4] with a dissertation on the concept of measurement.

Through the award of a Guggeheim Fellowship he was able to spend a year in Europe (from August 1934 to July 1935) to learn about the new trends in philosophy on the continent.

His work concerned the philosophy of mathematical fields such as geometry and probability, quantum mechanics, and the status of reductive and inductive theories of science.

Nagel's doctoral students include Morton White, Patrick Suppes, Henry Kyburg, Isaac Levi, and Kenneth Schaffner.