How to Prevent the Cooling of the Earth: A Page from God’s Cookbook

By Jean-Olivier Richard

Image from Athanasius Kircher’s Mundus Subterraneus (1678 edn.) vol. 1, p. 194.

Historians studying the relationship between climate and recipes (and yes, historians have good reasons to do so; see Jennifer A. Munroe’s post on seasonality and Katherine Allen’s articles on springtime in recipe books and the common cold) usually frame the question in terms of seasonality. In the pre-modern world, ingredients for recipes could often only be obtained in certain seasons or particular climates – the so-called seasonality of recipes. But the concept of recipe, provided one is willing to stretch its bounds, can also help us understand how our ancestors envisioned the role of God and Man in climate change and cosmic history. What if, for instance, one were to think of the Creation account of Genesis as a recipe? The metaphor is not as far-fetched as it may sound. Recipes entail not only ingredients and instructions, but also agency: isn’t God said to have made everything in measure, number, and weight (Wisdom 11:21)? Many early modern philosophers cherished this notion. Let us imagine, with one such philosopher, a page from God’s cookbook:

In the beginning, create the heaven and the earth. Everything should be in a state of chaos. Then, let there be light. Light will bring the world into sight by causing the formless abyss to sort itself out. Over a period of six days, let the sun, the moon, and the planets coalesce like bubbles, as celestial and terrestrial matter separate; on earth, concentric layers of air, water, and dry land will arise around a pulsing core of fire. In the process, bring forth minerals, plants, and animals. This is good, but not good enough. If the primordial light is left unchecked, all mixed and organic bodies will soon break down and dissolve into their elementary constituents; even beings endowed with seeds will stop propagating their kind. To prevent the cosmos from congealing, add Man to the mixture. Let him stir it, and it will be very good.

A caricature of Louis-Bertrand Castel’s “ocular organ” by Charles Germain de Saint Aubin (1721-1786).

The physics treatise that inspires my thought experiment appeared in 1724, when the boundaries between physical, chemical, and spiritual processes were still porous. Its author was the French Jesuit mathematician and natural philosopher Louis-Bertrand Castel (1688-1757), best remembered today for his ocular harpsichord (a musical instrument that played colors) and his quarrels with the likes of Voltaire and Rousseau. To be clear, Castel did not couch his interpretation of Genesis in culinary terms; but he did argue that God’s primordial “light” must refer to the fundamental, mechanical principle of nature, the force causing elementary particles to weigh against one another and to regroup according to their kind — like mercury, water, and oil mixed together end up settling into layers. What Moses called “light,” ancient philosophers like Empedocles, Parmenides, and Epicurus had known confusedly as “love and strife”, “sympathies and antipathies,” “attractions and repulsions.” Since Newton, moderns recognized it as “universal gravitation” — or as Castel would have it, “universal weighing” (pesanteur). Natural philosophy, just like the original chaos, was sorting itself out.

Yet universal weighing could only be half the story. Castel’s main contribution to science, as he saw it, was to demonstrate the need for another principle: a universal lightness, a kind of spiritual leaven or ferment that would counter the weight of nature and sprinkle a little chaos into the world’s regular march toward equilibrium. This principle had to be spiritual, as opposed to mechanical, because a constant mechanical counterweight would cancel out rather than interrupt the course of nature as needed. Now, God could intervene directly to do just that, but that would be beneath His dignity. A popular alternative — giving nature its own spiritual, vital powers — raised the specter of materialism; out of question for a Jesuit. Castel’s solution? God must have delegated the task of disrupting the world to Man, his troublesome steward. Endowed with free will, humans could bring about everything universal pesanteur could not. Local trouble, Castel reckoned, added up to all the meteorological, climatic, and geological changes needed to prevent the world from grinding to a halt and freezing over.

While this might seem to be a recipe for disaster, Castel trusted that God knew what He was doing. The curse of mortality, for one, ensured humans would not slack off, nor overreach their bounds. Since the Fall, Adam and his descendants felt the weight of nature; they had to sweat and toil to delay the hour of their death (death by gravity, that is). On the upside, tilling the land, breeding animals, cutting down trees, draining fens, building canals, mining the earth, manufacturing goods and transporting them for commerce—all this labor, along with the consumption and excretion of food, renewed the mixtures that nature constantly unraveled. Multiplied by the millions, local actions caused ripples: rain, winds, and waves to which Castel attributed weather pattern and climate change. When well concerted, human efforts made the earth compliant; when excessive or deficient, corrective backlashes ensued — storms, earthquakes, volcanic eruptions. On the whole, the world remained hospitable because man-made mixtures, combined with nature’s weighing and sorting action, preserved the planet’s internal circulation mechanism. Carried down by rivers, oceanic currents, and subterranean channels, the by-products of human activity fueled the central fire of the earth, the reservoir of heat for all living beings on the surface. Castel estimated that the sun only contributed a minute portion of heat compared to the earth’s inner furnace, hence the importance of keeping it alive.

Reproduced with kind permission from

Fifty years after Castel published his treatise, Georges-Louis Leclerc, Comte de Buffon (1707-1788) hypothesized that the earth was once a globe of molten rocks, whose age he ingeniously estimated by measuring the cooling rate of molten metal spheres. Revisiting the notion of a “central fire” keeping the planet warm from within, Buffon warned his readers about the inevitable freezing of the world, but also suggested that human industry might counter the process. Framed by debates about climate, gravity, progress, and the place of divine and human agency in nature, the Enlightenment saw scores of new ideas about the history of the earth — some of which presaging in surprising ways today’s anxieties about climate change. Yet Castel his contemporaries also expressed more confidence in human stewardship. Humans were God’s special ingredient in a perfectly well-balanced recipe; their 19th- and 20th-century successors would not be so serene.


Richard, Jean-Olivier. “The Art of Making Rain and Fair Weather: Life and World System of Louis-Bertrand Castel, SJ (1688-1757).” Ph.D. dissertation. Baltimore, Johns Hopkins University, 2016.

Castel, Louis-Bertrand. Traité de Physique sur la pesanteur universelle. Paris: Cailleau, 1724.

Buffon, Georges Louis-Leclerc, Comte de. Les Époques de la nature. Paris: Imprimerie royale, 1780.


‘Thus it prevails against its time’: distillation and cycles of nature in early modern pharmacy

By Tillmann Taape

In past centuries, devoid of freezers and heated greenhouses, the seasons affected medicines as well as foodstuffs. In addition to pickled vegetables and stored grain, early modern people worried about their provisions of healing plants and animal substances. These, too, had their season: many herbs were considered most powerful when picked in May, and ‘May dew’ collected from fragrant meadows at this time of year was said to have many healing properties. In his Destillierbücher (distillation manuals), published in the early sixteenth century, the Strasbourg surgeon-apothecary Hieronymus Brunschwig addresses the challenges which arise in pharmacy from nature’s cyclical changes. He explains that most preparations of fresh medicinal herbs are ‘unkeepable’. For example, ‘if you pound herbs, roots or other substances and squeeze the juice from it, then it becomes unpleasant, does not last, […] and soon putrid corruption ensues’.[1] Even with dried materia medica and compound drugs, their medicinal virtues faded over time.

Brunschwig knew this all too well from personal experience. As an apothecary running his own shop near the fish market, maintaining a stock of efficacious remedies was his chief responsibility and expertise. The issue of pharmaceutical provisioning was taken very seriously by Strasbourg’s magistrates. Twice a year, they would send round a committee of medical experts to all apothecary shops, to ensure that no perished goods were stocked, and to throw away any that had gone off.

An apothecary pounding medicines. Brunschwig, Liber de arte distillandi de compositis (Strasbourg, 1512), fol. 6v. © Wellcome Library, London

Brunschwig’s understanding of the material world was shaped by his experience as a pharmacist and shopkeeper, but also by the cosmology and medical theory of his day. While the heavenly spheres were characterised by material perfection and changelessness, all matter on earth was made up of the four elements (air, water,fire, earth) and subject to their constant permutations. They were doomed to endless cycles of generation, change, and decay. Material stability was only possible where the elements were in perfect balance, ‘as you can see in May when it is neither too dry nor too humid, neither too warm nor too cold’.[2]

Brunschwig’s seasonal simile is revealing: a perfect balance of elements is just as rare and fleeting as those precious few balmy weeks in May. As well as pointing to the instability of all earthly matter, the language of seasons and their cold, hot, dry or moist qualities was associated with early modern ideas about the stages of human life. Youth, health, reproduction, decline and death were analogous with the annual cycle of flourishing and decay in nature – a relationship which is richly illustrated in a set of anonymous seventeenth-century engravings (see here for an interactive digital reproduction). The idea of changing seasons was emblematic of an early modern view of the material world which was characterised by instability. Human bodies fluctuated with the shifting balance of their humours, and the very substances which could be used to cure the resulting ailments were themselves fleeting and, in Brunschwig’s words, ‘unkeepable’.

Faced with such difficulties, Brunschwig and others turned to a branch of knowledge with a longstanding commitment to imitating and manipulating natural processes underlying the transformations of matter: alchemy. In particular, Brunschwig describes distillation as a powerful artisanal technique to ‘keep the unkeepable’.[3] Distillation was the art of separation, and in the case of medicinal simples, Brunschwig claimed, their ‘soul’ or healing virtue could be separated from their ‘body’, that is to say the material dross made up of the problematic four elements. Thus liberated, the healing ‘spirit’ of a plant in the form of a distilled water could be bottled and neatly stored on Brunschwig’s alphabetically ordered shelf, where they would keep well beyond their harvest season, for up to three years. Later Destillierbücher echo the idea that one can ‘keep these waters over the year’ as a major selling point of distilled remedies.[4]

While distillation in theory had the power to produce pure and incorruptible ‘quintessences’, this was far too laborious for everyday pharmaceutical practice. Brunschwig wrote for an audience of ‘common men’ as well as artisan colleagues, and most of the distilled remedies he discusses are much more pedestrian. They still have some of the elemental qualities of the original herb, and are ultimately perishable. Compared to ‘unkeepable’ plant juice, however, their decay is slower and more predictable. Brunschwig confidently charts the decline and change in a water’s healing powers over the years, and even gives instructions for ‘recharging’ them. A water can be saved by infusing it with fresh herbs and distilling it once more – thus, Brunschwig reassures his readers, a distilled remedy can ‘prevail against its time’ for another year.[5]

In the early modern world of matter, the seasons symbolised cycles of change and decay which spelled trouble for healers and makers of medicines. In some of the earliest vernacular works on pharmacy, Brunschwig describes distillation as a powerful tool for defying the material corruption of seasonal changes.

[1] Brunschwig, Liber de arte distillandi de simplicibus… (Strasbourg, 1500), sig. C1v.

[2] Brunschwig, Liber der arte distulandi simplicia… (Strasbourg, 1509), fol. 36v.

[3] Brunschwig, Liber de arte distillandi de simplicibus… (Strasbourg, 1500), sig. C1v.

[4] Eucharius Röslin, Kreutterbuoch von allem Erdtgewaechs… (Frankfurt, 1533), title page verso.

[5] Brunschwig, Liber der arte distulandi simplicia… (Strasbourg, 1509), fol. 18v.