" Is it the quality of addictiveness that renders a substance illicit? Not in the case of tobacco, which I am free to grow in this garden. Curiously, the current campaign against tobacco dwells less on cigarettes’ addictiveness than on their threat to our health. So is it toxicity that renders a substance a public menace? Well, my garden is full of plants—datura and euphorbia, castor beans, and even the leaves of my rhubarb—that would sicken and possibly kill me if I ingested them, but the government trusts me to be careful. Is it, then, the prospect of pleasure—of “recreational use”—that puts a substance beyond the pale? Not in the case of alcohol: I can legally produce wine or hard cider or beer from my garden for my personal use (though there are regulations governing its distribution to others). So could it be a drug’s “mind-altering” properties that make it evil? Certainly not in the case of Prozac, a drug that, much like opium, mimics chemical compounds manufactured in the brain. "

― Michael Pollan , This Is Your Mind on Plants