Although human engagement with drugs is effectively without a beginning, ‘drug’ as a concept emerged only with written history. The oldest and longest Egyptian medical text, the Ebers Papyrus, which dates from around 1600 BC, describes the roots, seeds and heads of the poppy plant; other texts suggest it was recognized as an analgesic, but it is impossible to be sure whether this effect was specifically attributed to its opium sap, or whether the plant was used, as it has apparently been since deep prehistory, for other purposes: food, medicine, incense or ritual. With the ancient Greeks, the notion of a drug came into sharper focus. Around 300 BC Theophrastus, a colleague of Aristotle, wrote two botanical treatises in which he designated certain plants as pharmaka, a term spanning the senses of ‘drug’, ‘cure’ and ‘poison’. A comparable range of meanings survives in the English word ‘intoxicant’, in which concepts of altered consciousness and poisoning are similarly entwined.
Drugs, however, were a comparatively small part of medicine in the classical world. The Hippocratic tradition that emerged in the decades before Theophrastus recognized their power to act in certain conditions, but tended to assign them only a minor role in the drama of healing. The physician’s art encompassed a spectrum of performance and ritual that involved not just the disease but the patient as a whole, drawing them in to perform their own cures. Medicinal drugs were catalogued and given broad characteristics, such as ‘purgative’ or ‘emollient’, but they were not magic bullets: they were suited to one type of patient rather than another, and prepared or administered in a variety of subtle ways, though most commonly stirred into oil and wine. Generalizing from one cure to another, as itinerant drug peddlers did with their wares, was regarded as ignorant and mechanistic: each patient’s therapy should be a bespoke creation.
Within this framework, the category of drugs was loosely defined, and hard to extricate from other categories such as foods (the distinction is not entirely clear today: we still use prunes as a remedy for constipation, and cloves as a palliative for toothache). Plant drugs were not conceived as chemical substances contained in the root, seed or flower, but as aspects of the plant’s overall personality. Modern ideas of drug chemistry and action were not sought for, or missed. Given the limited range of drugs available, and the considerable ability of good physicians to harness what is now known as the placebo effect, Hippocratic healing was a natural product of its age.
As knowledge of plants was systematized, the figure who came to be the unrivalled authority on their medical uses was Pedanius Dioscorides. Born in Asia Minor, in what is now south-eastern Turkey, shortly after the time of Christ, Dioscorides was perfectly placed to weave the disparate threads of botany and healing into the nascent discipline of pharmacy. The school of Tarsus, where he studied, had specialized in plants and medicine for generations: it was located at a crossroads, between Mediterranean Europe, Egypt and India, from where resins such as frankincense and spices such as cloves and cinnamon flowed into the West. Dioscorides’ Materia medica listed over a thousand drugs, classified by animal, vegetable or mineral origin, together with keenly observed descriptions of what each drug ‘did’ and instructions on how it should be used.
It is in Materia medicas fourth chapter, on medicinal roots and herbs, that we find the first descriptions of many drugs with psychoactive effects loosely grouped together. Narcotic, stimulant and depressant effects are separated, though all are discussed within the framework of pharmacology rather than pleasure (‘causes sleep’, ‘causes frenzies’ or ‘eases pain’). Although he gives brief descriptions of their psychoactive effects, he is more focused on their dangers. For Dioscorides, the property that links mind-altering drugs, from the narcotic opium to the deliriant nightshades, is that they are ‘cold’ or ‘cooling’: by this he means that their effect, over increased doses, is to dull sensitivity to the outside world along a spectrum ranging from sedation or fever to sleep, and eventually to overdose and death. The leaves of the thornapple, Datura stramonium, for example, taken in liquid at a dose of one drachm (4 grams) produce ‘not unpleasant fantasies’; but two drachms overcomes the subject completely for three days, and four drachms is fatal. It was too crude, therefore, for Dioscorides to speak of ‘the effects’ of a drug: its properties lie not in the substance itself but the dose at which it is taken.
World History
