Speculations on the Origin of Human Intelligence:
"In defense of the Pygmies, perhaps I should note that a friend of mine who has spent time with them says that for such activities as the patient stalking and hunting of mammals and fish they prepare themselves through marijuana intoxication, which helps to make the long waits, boring to anyone further evolved than a Komodo dragon, at least moderately tolerable.
Ganja is, he says, their only cultivated crop. It would be wryly interesting if in human history the cultivation of marijuana led generally to the invention of agriculture, and thereby to civilization.
"Carl Sagan - The Dragons of Eden 1977"