Terra Incognita. Alain Corbin
became a hot topic for debate prior to the Lisbon disaster, though the event certainly also drove the process subsequently.
From the point of view of a history of ignorance, the most important issue is that scholars began to ask questions: what triggered the disaster and how did it unfold? From 1755 on, the French Academy of Sciences launched a fully fledged earthquake research programme10 that built an archive of such events. According to the Journal encyclopédique [Encyclopedic Journal] of 1 May 1756, ‘All physicists are working to find the actual cause of earthquakes. […] The cleverest circles […] are making it a topic of conversation.’ Of particular interest for this book is the article’s claim that ‘even the ignorant dare talk about it. […] In a word, everyone wants to discover this terrible secret of nature.’11
The mid-eighteenth century saw the rise of subscription libraries and educational and scientific publications. The closing quarter of the century was a golden age of popular scientific debate. In this context, the problem of earthquakes was still widely discussed in fashionable salons at the end of the century. It is no exaggeration to call this the ‘earthquake craze’,12 akin to the fashion for hot-air ballooning. Even the rural population took an interest in the topic. The curiosity and suffering caused by the shortfall in scientific knowledge were still intense in the closing years of the eighteenth century, though curiosity about earthquakes was tending to give way to an interest in volcanoes. Even so, a play about the Great Lisbon Earthquake was still being performed in Paris in the very early nineteenth century. As late as 1878, a set of clockwork figures was shown in Orleans, performing two events from history: Joan of Arc delivering the city – and the Lisbon earthquake.
Scholars spent the half-century following the disaster arguing about its causes. Lisbon opened up a space for debate. Three types of explanation were put forward. The first argued for a subterranean inflammation of sulphurous and bituminous matter, attributing the earthquake to an underground fire. The second, which held most sway in the latter half of the century, believed that a dilation in the air triggered the tremors. This explanation was driven by the fashion for studying the physical properties of gases. The third explanation was based on theories of electricity that were highly popular at the end of the century; it held that the disaster was caused by the instantaneous propagation of electric fluid through all conducting bodies.
What is most interesting is that people were now trying to understand the disaster, to interpret it, protect themselves from its effects and measure its impact on society, quite apart from the question of salvation. The catastrophe played a significant role in establishing the earth sciences.
At the same time, a new research focus on fossils and the fledgling study of geological strata led to renewed challenges to the unity and universality of the Great Flood, as scholars began to posit a series of local floods and modify their thinking about the age of the earth.
The Lisbon earthquake and the series of disasters that followed it also had an impact on the emotional range of responses to such cataclysms. From that point on, descriptions of the destruction they wrought and their scientific study went hand in hand with the expression of a feeling of pity and compassion for those affected. There was also sometimes an urge to aestheticize the tragedy – a point I will return to later. A new fear took over from the fear of divine wrath: the potential collapse of civilization. This feeling is still with us today.
We now turn to the cognitive and emotional consequences of the Lisbon earthquake. It was long argued that Voltaire’s poem about the disaster set out to radically challenge God’s goodness and the optimistic philosophy of Leibniz’s Theodicy. This is true as far as it goes, but requires further explanation. Unlike d’Holbach, Voltaire did not wholly exclude God from his reflections and his denunciation. He doubtless thought society was not yet ready for a fully secular response to natural disasters. Diderot was more outspoken in his opinion that it was ‘the movement inherent in matter, not the will of God that transforms the world’;13 Jean-Jacques Rousseau held that natural disasters such as volcanic eruptions, major earthquakes and terrible fires caused by lightning were the cause of the social state, since they brought men together in large numbers to repair the damage. More immediately relevant for a history of ignorance are the gaps in knowledge filled by the Lisbon earthquake, which revived libido sciendi, the thirst for knowledge. In this context, the disaster proved a turning point. As well as the printed press, handwritten communications in the form of letters and even handcopied gazettes played a significant role. Later sources documented the importance of oral memory in handing details of the Lisbon earthquake all the way down to the late nineteenth century. Grégory Quenet has argued that the event ‘led to an unprecedented unification of Europe, perhaps unrivalled until the French Revolution’.14 The Lisbon earthquake long remained the archetypal deadly disaster in the European imaginary, almost completely supplanting the Lima earthquake of 1751.
I have chosen to take the Lisbon disaster as a key date marking a turning point in the history of contemporary representations of the earth. Between 1755 and the opening decades of the nineteenth century, a series of questions and issues were hotly debated, demonstrating gaps in contemporary knowledge, the first hesitant steps towards filling them in, and a lack of clarity in how even the most cultivated thinkers pictured the earth and sought to understand its secrets.
It is worth briefly stating the main issues explored as part of this wide-ranging debate, which varied across the social spectrum:
1 How old is the earth? How best to understand the timescales of its history?
2 What is inside the earth? Fire, water or viscous matter? This question gave rise to theories on earthquakes: when these became fashionable, the same process was extended to volcanoes, with various interpretations put forward to explain the magnificent spectacle.
3 A series of questions focused on the poles, which lay beyond human reach at that point. Did they have inner Arctic and Antarctic seas? Where did sea ice come from?
4 Before the first mountaineering expeditions, how did people think geological strata and mountains were formed?
5 What did they think about glaciers and mountain topography?
6 What was the meaning of the first major fossil discoveries, for instance in Siberia?
7 In an age when men were fascinated by storms and hurricanes, how did such weather phenomena form and grow so violent? (This was a time when remote regions were only just beginning to come into focus, leading to a new interpretation of space – a point I will return to later.)
When studying the history of ignorance, it is crucial to foreground the lack of certainties and the sheer scale of the gaps in common knowledge. Even the most erudite of scholars asking profound questions had barely more information at their fingertips than those content to leave the questions unasked. Since Aristotle’s theories had been discredited, undermining the solid core of certainties that had satisfied libido sciendi for centuries, Enlightenment scholars were asking many new questions. However, as we will see, very few gaps in knowledge about the earth were actually filled with any certainty. Diderot and d’Alembert’s Encyclopédie [Encyclopedia] and similar works of Enlightenment scholarship offer the reader an inventory of uncertainties and lacunae waiting to be filled.
NOTES
1 1. These opening paragraphs were inspired by Thomas Labbé’s recent major work of scholarship, Les Catastrophes naturelles au Moyen Âge. Paris: CNRS, 2017, pp. 185, 188.
2 2. Petrarch, Letters on Familiar Matters, vol. 1, tr. Aldo S. Bernardo. New York: Italica, 2005, p. 245.
3 3. Jean Delumeau, La Peur en Occident, XIVe–XVIIIe siècle: Une cité assiégée. Paris: Fayard, 1978.
4 4. Labbé, Les Catastrophes naturelles, pp. 294–5.
5 5. The importance of signs of catastrophe is highlighted by Thomas Labbé and by Philippe Bénéton, whose study of Niccolò Massimo (Niccolò Massimo: Essai sur l’art d’écrire de Machiavel. Paris: Cerf, 2018) focuses at length on the importance of disasters as signs in Machiavelli’s