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

[1] "Between these two extremes are spread out in a continuous sequence the spectral lines of the more sedate, human attitudes.

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.

"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.