More excerpts from Wikipedia‘s substantive entry on “1755 Lisbon earthquake,” at http://en.wikipedia.org/wiki/1755_Lisbon_earthquake
Effect on society and philosophy
The earthquake had wide-ranging effects on the lives of the populace and intelligentsia. The earthquake had struck on an important church holiday and had destroyed almost every important church in the city, causing anxiety and confusion among the citizens of a staunch and devout Roman Catholic city and country, which had been a major patron of the Church. Theologians and philosophers would focus and speculate on the religious cause and message, seeing the earthquake as a manifestation of the anger of God.
The earthquake and its fallout strongly influenced the intelligentsia of the European Age of Enlightenment. [Cf the recent posts on Voltaire and Rousseau in response to the Lisbon event, which brings us to another, oft-cited thinker on Makurrah’s Blog. You guessed it.] …. The concept of the sublime, though it existed before 1755, was developed in philosophy and elevated to greater importance by Immanuel Kant, in part as a result of his attempts to comprehend the enormity of the Lisbon quake and tsunami. Kant published three separate texts on the Lisbon earthquake. The young Kant, fascinated with the earthquake, collected all the information available to him in news pamphlets, and used it to formulate a theory of the causes of earthquakes. Kant’s theory, which involved the shifting of huge subterranean caverns filled with hot gases, was (though ultimately shown to be false) one of the first systematic modern attempts to explain earthquakes by positing natural, rather than supernatural, causes. According to Walter Benjamin, Kant’s slim early book on the earthquake “probably represents the beginnings of scientific geography in Germany. And certainly the beginnings of seismology.”
Werner Hamacher has claimed that the earthquake’s consequences extended into the vocabulary of philosophy, making the common metaphor of firm “grounding” for philosopher’s arguments shaky and uncertain: “Under the impression exerted by the Lisbon earthquake, which touched the European mind in one [of] its more sensitive epochs, the metaphor of ground and tremor completely lost their apparent innocence; they were no longer merely figures of speech” [Hamacher, Premises, 263]. Hamacher claims that the foundational certainty of Descartes’ philosophy began to shake following the Lisbon earthquake.
Hamacher’s “The Quaking of Presentation” in Premises: Essays on Philosophy and Literature from Kant to Celan is among the most authoritative and reliable sources I know on these matters.