“All the naturally occurring sedatives, narcotics, euphorics, hallucinogens, and excitants were discovered thousands of years ago, before the dawn of civilization. This surely is one of the strangest facts in that long catalogue of improbabilities known as human history. It is evident that primitive man experimented with every root, twig, leaf, and flower, every seed, nut, berry and fungus in his environment. Pharmacology is older than agriculture. There is good reason to believe that even in paleolithic times, while he was still a hunter and a food-gatherer, man killed his animal and human enemies with poisoned arrows. By the late Stone Age, he was systematically poisoning himself.”