In a notebook he kept while imprisoned in the late 1960s, Régis Debray recorded a scene from Che Guevara’s final ill-fated mission in Bolivia. The authorities had arrested the young philosopher as an accomplice to the guerrillas  — something he denied, never very plausibly. That is how his oeuvre came to include a volume called Prison Writings.

Comandante Che, known to his troops as Ramón, carried “a whole library on his back,” writes Debray, “which his comrades gradually managed to insist on sharing, to lighten his load.” They probably regretted doing so soon enough. Books were “a fearful load when added to the ammunition clips, the bags of rice and sugar, the bottle of oil, and so on.” Marching through the jungle day after day could only make the difference between a luxury and a necessity feel keener. No doubt the men were tempted to “lose” a few books along the way.