"When Sigmund Freud first suggested that everybody has elaborate sexual fantasies, that it is as natural as breathing, he was dismissed as a pervert and lunatic. People wanted to believe that sexual fantasy was something that happened in other people — filthy people, dirty people. They took the parts of their subconscious that generated these wet dreams and daydreams and projected them onto somebody else, the depraved people Over There, who had to be stopped. Stuart Walton and the philosopher Terence McKenna both write that we are at this stage with our equally universal desire to seek out altered mental states. McKenna explains: 'We are discovering that human beings are creatures of chemical habit with the same horrified disbelief as when the Victorians discovered that humans are creatures of sexual fantasy and obsession.'

"Just as we are rescuing the sex drive from our subconscious and from shame, so we need to take the intoxication drive out into the open where it can breathe. Stuart Walton calls for a whole new field of human knowledge called 'intoxicology.' He writes: 'Intoxication plays, or has played, a part in the lives of virtually everybody who has ever lived ... To seek to deny it is not only futile; it is a dereliction of an entirely constitutive part of who we are.'

"After twenty-five years of watching stoned mice, drunken elephants, and tripping mongooses, Ronald K. Siegel tells me he suspects he has learned something about this. 'We're not so different from the other animal lifeforms on this planet,' he says.

"When he sees people raging against all drug use, he is puzzled. 'They're denying their own chemistry,' he says. 'The brain produces endorphins. When does it produce endorphins? In stress, and in pain. What are endorphins? They are morphine-like compounds. It's a natural occurrence in the brain that makes them feel good ... People feel euphoric sometimes. These are chemical changes — the same kind of chemical changes, with the same molecular structures, that these plants [we use to make our drugs] are producing ... We're all producing the same stuff.'

"Indeed, he continues, 'the experience you have in orgasm is partially chemical — it's a drug. So people deny they want this? Come on! ... It's fun. It's enjoyable. And it's chemical. That's intoxication.' He seems for a moment to think back over all the animals guzzling drugs he has watched over all these years. 'I don't see,' he says, 'any difference in where the chemical came from.'

"This is in us. It is in our brains. It is part of who we are."