So long as man remains free he strives for nothing so incessantly and so painfully as to find someone to worship.
I would like now to turn to a related subject, and that has to do with the influence of molecules on the emotions and perceptions. By molecules I just mean chemicals-natural chemicals in the environment or synthetic chemicals made in laboratories. We, of course, all understand that behavior is modified by molecules. Humans all over the world have had experience with substances like ethanol that certainly produced changes in behavior and attitudes and perceptions of the world. We know about tranquilizers that likewise do that. But let us consider a very specific case, and that is manic-depressive syndrome. It's a terrible disease. The manic-depressive swings between two extremes, and it's hard for me to see which is more ghastly: one in the utter pit of despair and the other a kind of high-flying exaltation in which everything seems possible-to the extent that many sufferers of this disease when they are at the manic end of the pendulum believe that they are God. And this is, of course, disabling. Both ends of the swing are disabling, and you don't spend much time in the middle, just like a pendulum, in which you move more slowly at the ends than you do through the middle. It's a disease found in every human culture, and until the last two or three decades there was no effective treatment. Well, there is now a material that powerfully ameliorates manic-depressive syndrome in many patients, provided the dose of this material is administered very carefully. People who have taken this substance in regularly controlled doses, many of them, find that they are able to function again. Their lives are normalized, and they consider it a great blessing. What is this material? It is lithium, a salt. Lithium is a chemical element, the third simplest after hydrogen and helium. It's astonishing that such a simple material could have so profound an effect on a subset of the human population and change not just behavior; if you talk to ex-manic-depressives-that is, manic-depressives whose disease is controlled by regular administration of lithium-their account from the inside of how transforming this treatment is, is really stunning.
Now, bearing this in mind, who will say that there are human emotions that will not, at least one day, be understood in some fundamental manner in the language of molecular biology and neuronal architecture? If you run through our own society and other societies, you find a vast range of substances, many of them chemically very distinct, that powerfully affect mood and emotion and behavior. Not just ethanol but caffeine, mushrooms, amphetamines, tetrahydrocannabinol and the other cannabinoids, lysergic acid diethylamide-known as LSD- barbiturates, Thorazine. It's a very long list.
This prompts certain questions: Are all human emotions to some extent mediated by molecules? If a molecule ingested from the outside can change behavior, is there generally some comparable molecule on the inside that can change behavior? This is now a field that has made remarkable progress. I'm talking about the enkephalins and the endorphins, which are small brain proteins.
In labor, women are amazingly strong in bearing pain, and of course there is a great deal of pain in childbirth. But in that case and in many other traumatic situations, the human body produces a particular molecule that reduces our susceptibility to pain. And it does it for very good survival reasons, which are not hard to understand. There are specific receptors in the brain for these small brain proteins, and it turns out that the opiates ingested from the outside are extremely similar chemically to a particular enkephalin having to do with resistance to pain that is produced on the inside; that is, it is looking as if every time a molecule on the outside does something about human emotions, there is a related molecule on the inside that is naturally produced, which is how it is that we have a brain receptor for this particular kind of molecular functional group.
Let me be a little less abstract and speak from personal experience. I go to the dentist, and he gives me an injection of Adrenalin. It is a molecule. It's a molecule produced in your body, but it's also produced outside. And every time I've had this injection, I'm almost overcome with two contradictory emotions, one of which is to attack the dentist and the other is to leave the dentist's office, both of which I suppose could be understood just on purely rational grounds, considering the circumstances. But this is what adrenaline, the hormone epinephrine, does under any circumstances, under the most benign circumstances. It's called the fight-or-flight syndrome. This molecule makes you either aggressive or, if you want to think about running away, cowardly, one or the other. Very remarkable that two such apparently contradictory emotions can be brought about by the same molecule. But more important than that, it's extremely interesting. They just put this molecule in your bloodstream, and suddenly you feel things. It's just a function of the molecule being there. It's nothing, necessarily, in the external world. And we can understand the reasons for that. Consider our remote ancestors faced with, let us say, a pack of hyenas, not having yet deduced that hyenas with fangs bared are dangerous. It would be too inefficient to have our ancestor consciously stop and think, "Oh, I see those beasts have sharp teeth; they probably can eat somebody. They're coming at me. Maybe I should run away." By then it's too late.
What you need is one quick look at the hyena, and instantly the molecule is produced, and you run away, and later you can figure out what happened. And you can see two populations, one of whom has to slowly think the matter out, the other of whom can rapidly respond to the adrenaline. After a while these guys leave lots of offspring, those guys don't. Everybody winds up generating adrenaline. Natural selection. Not hard to understand how that comes about. And there are, of course, many other molecules like that.
Another one is testosterone, which is produced in males at adolescence and instigates all sorts of bizarre behavior that we all know. I don't want to suggest that at the same age I was immune from it. I personally know the consequences of testosterone poisoning. You might imagine that our distant ancestors could figure out that it was useful to propagate the species and leave offspring and had an intellectual understanding of how it comes about. But this is very iffy. It's requiring a great deal of intellectual activity and cerebration, and it's much better to simply have the whole thing hardwired in the brain and triggered by this molecule after the biological clock has ticked away for a certain period of time. And so the presence of an attractive member of the opposite sex immediately leads to this sequence of events, and the species continues.
There are many other such molecules. Of course, females have estrogen and other hormones. The number of sex hormones is more than one each. Statistics on the subjects that adults of all ages dream about most have sex very high up, and everything else is far below. It's clear the more interested in sex people are, generally speaking, the more offspring they tend to leave, at least before the invention of birth-control devices, and so there is a selective advantage for each species to have this kind of internal machinery.
In just the same ways as the enkephalins and the endorphins and sex hormones influence our sexual activity, what about hormones and religion? People certainly have spontaneous religious experiences. Sometimes they're brought about by deprivation, as with the fasting monks in the desert. There are a number of ways in which sensory deprivation can bring about these experiences. They also happen spontaneously to people in many different cultures, always using the language of the indigenous culture to describe the experience. But also they can be brought about in a molecular way. And certainly the uniform experience, especially in the 1950s and '60s-pioneered by Aldous Huxley and others-was that LSD and other such molecules produce religious experiences. And there were many religionists who objected to this, because they thought it was too easy; that is, you're not supposed to have a religious experience without doing some significant personal deprivation. Just taking, whatever it was, five hundred micrograms of a tablet, was considered too easy.