failed to distinguish between physical and mathematical division – a problem that was overcome after Aristotle’s death by Epicurus (341–270 BC), who allowed that, although atoms were the unsplittable physical minima of matter, because an atom had definite size, it could be said to contain mathematically indivisible parts. Epicurus also explained the compounding of atoms together as they fell with equal speeds through the void as due to sudden ‘swerves’ or deviations. These unpredictable swerves are a reminder that atomism, as popularized in Epicurean philosophy, had more to do with the establishment of a moral and ethical philosophy than as an interpretation of the physics and chemistry of change. Swerving atoms allowed for human free will. Atomism for the Epicureans, as well as for its great poetic expositor, the Roman Lucretius in De rerum natura (c. 55 BC), was a way of ensuring human happiness by the eradication of anxieties and fears engendered by religions, superstitions and ignorance. Ironically, in the sixteenth century, atomism began to be used as a way of eliminating the superstitions and ignorance of Aristotelianism.
The other great post-Aristotelian system of philosophy, Stoicism, because it adopted and adapted considerable parts of Aristotelianism, was more influential. Founded by the Athenian, Zeno (342–270 BC), during the fourth century BC and refined and developed up to the time of Seneca in the first century AD, Stoicism retained Aristotle’s plenistic physics and argued for the indefinite divisibility of matter. Stoics laid stress on the analogy between macrocosm and microcosm, the heavens and the earth, and distinguished between inert matter and a more active form, the latter being called the pneuma, or vital spirit. Pneuma pervaded the whole cosmos and brought about generation as well as decay. Ordinary substances, as Empedocles and Aristotle had taught, were composed from the four elements, albeit hot and dry, fire and air were more active than passive wet and cold, water and earth. From this it was but a short step to interpreting air and fire as forms of pneuma, and pneuma as the glue or force that bound passive earth and water into cohesive substances. The concept was to have a profound effect on the interpretation of distillation.
Chemical compounds (an anachronism, of course) were mixtures of these four elements in varying proportions – albeit Aristotle’s and the Stoics’ views were rather more sophisticated than this bald statement suggests. The central theorem of alchemy, transmutation, could be seen in one of two ways, either as what we would call chemical change caused by the different proportions of elements and their rearrangement, or as a real transmutation in which the qualities of the elements are transformed. Alchemy allowed far more ‘transmutations’ than later chemistry was to allow, for it permitted the transmutation of lead or other common metals into gold or some other precious metal. A real transmutation of lead and gold was to be achieved by stripping lead of its qualities and replanting the basic matter that was left with the qualities and attributes of gold. Since lead was dense, soft and grey, while gold was dense, soft and yellow, only a change of colour seemed significant. However, although alchemy is usually taken to be the science of restricted metallic transmutations, it is worth emphasizing that it was really concerned with all chemical changes. In that very general sense, alchemy was the basis of chemistry.
One of the most important geographical areas for the creation of alchemy was Egypt during the Hellenistic period from about 300 BC to the first century AD. Egypt was then a melting pot for Greek philosophy, oriental and Christian religions, astrology, magic, Hermeticism and Gnosticism, as well as trade and technology. Hermeticism, which took its title from Hermes, the Greek form of the Egyptian deity, Thoth, the father of all book learning, was a blend of Egyptian religion, Babylonian astrology, Platonism and Stoicism. Its vast literature, the Hermetic books, supposedly written by Hermes Trismegistus, was probably compiled in Egypt during the second century BC. Gnosticism, on the other hand, was an ancient Babylonian religious movement, which stressed the dualism between light and darkness, good and evil. Gnosis was knowledge obtained only through inner illumination, and not through reason or faith. Humankind was assured of redemption only from this inner enlightenment. Gnosticism both competed with early Christianity and influenced the writing of the Gospels. As its texts show, however, Gnosticism was as much influenced by contemporary alchemy as it influenced alchemical language. For example, in the Gnostic creation story, chemical expressions referring to sublimation and distillation are found, as in the phrase ‘the light and the heavy, those which rise to the top and those which sink to the bottom’. The most important of the Gnostics, Theodotos, who lived in the second century AD, used metaphors of refining, filtering, purifying and mixing, which some historians think he may have drawn from the alchemical school of Mary the Jewess. When Gnostic language is met in alchemical texts of the period, such as the Dialogue of Kleopatra and the Philosophers, however, it is difficult to know whether the author is referring to the death and revivification of metals or to the death and regeneration of the human soul. Exoteric alchemy had become inextricably bound with esoteric alchemy.
Most historians have seen three distinctive threads leading towards the development of Hellenistic alchemy: the empirical technology and Greek theories of matter already referred to, and mysticism – an unsatisfactory word that refers to a rag-bag of magical, religious and seemingly irrational and unscientific practices. Undoubtedly this third ingredient left its mark on the young science, and it in turn has left its mark on ‘mysticism’ right up until the twentieth century. In Hellenistic Egypt, as in Confucian China, there was a distinctive tendency to turn aside from observation and experiment and the things of this world to seek solace in mystical and religious revelations. It was the absorption of this element into alchemy that splintered its adherents into groups with different purposes and which later helped to designate alchemy as a pseudo-science.
Recent studies have shown the considerable extent of pharmacological knowledge within the Arabic tradition. This tradition was to furnish the Latin west with large numbers of chemical substances and apparatus. It was clearly already well established in Greek alchemy, and it is to medicine that the historian must also look for another of alchemy’s foundation stones. For it was the Greek pharmacists who mixed, purified, heated and pulverized minerals and plants to make salves and tinctures. In Greek texts the word for a chemical reagent is, significantly, pharmakon.
The modern conspectus is, therefore, that practical alchemy was the bastard child of medicine and pharmacy, as well as of dyeing and metallurgy. By applying Aristotelian, Neoplatonic, Gnostic and Stoic ideas to the practices of doctors and artisans, Greek alchemists reinterpreted practice as transmutation. This point is especially clear in a seventh-century AD text by Stephanos of Alexandria, ‘On the great and sacred art, or the making of gold’, in which he attacked goldsmiths for practising aurifiction. If such craftsmen had been properly educated in philosophy, he commented, they would know that gold could be made by means of an actual transformation.
For one group of such-minded alchemical philosophers, astrology, magic and religious ritual grew at the expense of laboratory and workshop practice. Alchemical symbolism and allegory appealed strongly to the early Gnostics and Neoplatonists. The ‘death’ of metals, their ‘resurrection’ and ‘perfection’ as gold or purple dyes were symbolical of the death, resurrection and perfection of Christ and of what should, ideally, happen to the human soul. This esoteric alchemy is more the province of the psychologist and psychiatrist, as Jung claimed, or of the historian of religion and anthropology, than of the historian of chemistry. Nevertheless, as in the case of Isaac Newton, the historian of science must at all times be aware that, until the nineteenth century at least, most scientific activities were, fundamentally, religious ones. The historian of chemistry must not be surprised to find that even the most transparent of experimental texts may contain language that is allegorical and symbolical and which is capable of being read in a spiritual way.
Exoteric alchemists continued their experimental labours, discovered much that was useful then and later, and suffered the indignities of bad reputation stemming from less noble confidence tricksters. Another group became interested in theories of matter and promoted discussion of ideas of particles, atoms or minima naturalis. Finally, the artisans and technologists continued with their recipes, uninterested in theoretical abstractions.
The primitive notion that metals grew
