The ways in which humans use plants, foods, and drugs cause the values of individuals and, ultimately, whole societies to shift. Eating some foods make us happy, eating others sleepy, and still others alert. We are jovial, restless, aroused, or depressed depending on what we have eaten. Society tacitly encourages certain behaviors that correspond to internal feelings, thereby encouraging the use of substances that produce acceptable behaviors.
Suppression or expression of sexuality, fertility and sexual potency, degree of visual acuity, sensitivity to sound, speed of motor response, rate of maturation, and lifespan-these are only some of animal's characteristics that can be influenced by food plants with exotic chemistries. Human symbol formation. linguistic facility, and sensitivity to community values may also shift under the influence of psychoactive and physiologically active metabolites. A night spent observing behavior in a singles bar should be fieldwork enough to confirm this observation. Indeed the mate-getting hustle has always placed a high premium on linguistic facility, as perennial attention to patter styles and opening lines attests.
When thinking about drugs, we tend to focus on episodes of intoxication, but many drugs are normally used in subthreshold or maintenance doses; coffee and tobacco are obvious examples in our culture. The result of this is a kind of "ambience of intoxication." Like fish in water, people in a culture swim in the virtually invisible medium of cuturally sanctioned yet artificial states of mind.
Languages appear invisible to the people who speak them, yet they create the fabric of reality for their users. The problem of mistaking language for reality in the everyday world is only too well known. Plant use is an example of a complex language of chemical and social interactions. Yet most of us are unaware of the effects of plants on ourselves and our reality, partly because we have forgotten that plants hace always mediated the human cultural relationship to the world at large.
Terence McKenna "Food of the Gods"