The Yogi and the Commissar (1945) is a collection of essays of Arthur Koestler, divided in three parts: Meanderings, Exhortations and Explorations.

On the other hand, this increase of wool on the naked spectral bodies makes them look more decent and intercourse with them more civilized.

"[2]Using a metaphor of spectra of radiation, Koestler figures the Commissar at the infra-red end of the spectrum; the Yogi is ultra-violet.

Neither are in the realm of visible light, he suggests, and just so the full dynamics of history and culture escape us.

"The Birth of a Myth", one essay published in Horizon in April 1943, appeared as "In Memory of Richard Hillary" in a longer version at pages 46–67.