History and Historiography of Science

Primer: Lyell’s Principles of Geology

For today’s post, I want to talk about one of the most influential books in the natural sciences, Charles Lyell’s Principles of Geology, published in three volumes from 1830 to 1833.  Lyell (1797-1875) was an English gentleman, who turned to scientific study at university after originally intending to train to be a barrister.  His entry to geology came at a time when the field was becoming increasingly professionalized; Principles was his attempt to bring some philosophical rigor to the subject, to lend it further respectability as a modern, 19th-century “science”, that is, the sense that the term now connotes.

By the time Lyell wrote the Principles, mainstream geological opinion (and also some religious opinion) accepted that Biblical chronologies could not be maintained in light of fossil evidence.  Debates had thus turned to the various problems of “deep history”, such as: what had happened in the past, how the earth began and whether it was headed for an end, and whether geological history followed a clear progressive arc from an initial to a final state.  Lyell was eager to set aside the speculative practices of natural philosophical “universal” histories, and to ground geological accounts on a clear set of principles, effectively a palette of known geological processes.  He consciously took his title in the tradition of Newton’s Mathematical Principles of Natural Philosophy.

Charles Lyell

Lyell advocated that geologists travel extensively to expand the palette of geological phenomena and processes as much as possible, but insisted that this palette be restricted within the bounds of what could be witnessed.  Accordingly, he refused to include the possibility of catastrophic change in the evolution of the earth among his “principles” (despite widespread speculation that certain dramatic landscape features could only be produced by catastrophic processes), because he felt that only processes that had actually been witnessed ought to be accepted as possible mechanisms of geological change.  Contrary to his critics’ accusations, this did not mean that he discounted the possibility of catastrophic change; rather he felt that resorting to such explanations constituted an unduly speculative approach to explaining geological history.  Lyell accepted that complete accounts of the geological past could never be achieved, and was willing to sacrifice seemingly safe extrapolations from evidence for methodological rigor.

Thus, for similar reasons, Lyell saw no possibility of obtaining evidence about whether geological history had a firm beginning, and so refused to posit any account of that beginning.  But that should not be taken to mean he discounted the possibility altogether, only that it could not be discussed in a rigorous way.  His position here set him apart from those who sought to explain geological problems as a result of the earth’s cooling from an initial molten state (“vulcanists”), or a sea level that decreased with time from an initially high level (“neptunists”).

Lyell was, of course, a critic of religious Diluvian accounts that sought to rescue Biblical chronology by resorting to Noah’s flood as a catch-all explanation for geological oddities, and often unfairly lumped his “catastrophist” opponents, who allowed for radical change but acknowledged the depth of geological time, in with religious orthodoxy.  At the same time, Lyell wrote for a wide audience, and was careful not to offend religious sensibilities by adopting a prosecutorial tone.  Rev. Henry Milman’s History of the Jews, which adopted a dryly historical tone, had sparked public controversies.  Lyell was successful in avoiding them.  Even those religious reviewers who felt he was being speculative or in error still lauded the book for its sober and detailed arguments.

Of course, Lyell was himself eager to preserve humanity as a special species not subject to naturalistic accounts, and took an explicit anti-evolutionary position with respect to living things.  Thus, he was a strong opponent of the evolutionary accounts of life put forward by Jean-Baptiste Lamarck, and accepted by many others on the Continent.  Instead, he held a position linking species to the climate for which they were suited, and supposed that as climates changed, extinct species might return, but that this process would not happen in any linearly progressive way.  For this reason, Lyell was sometimes grouped with those who felt the earth was eternal.  Ironically, this is the same argument that inspired Darwin’s thinking as he read Lyell on board the Beagle.  Later in life, Lyell would join Darwin among Britain’s naturalist elite, and would come to accept the evolution of species, which he had initially vehemently opposed.

I was inspired to do this post, because the Penguin edition of Lyell’s Principles was among my recent online random book purchases, stuff that I thought might come in handy in the future (also bought, Rick Perlstein’s Nixonland, which turns out to be a good example of a book that assembles well-known arguments and reasonably well-known events into a remarkably lucid popular portrait, in this case of the evolution of American cultural politics).  This edition of Principles contains an introduction by Jim Secord, which turned out to be a shockingly well-executed compact analysis of the work, its strategies, its context, and its impact—a model example of the consolidation of historiographical gains, complete with opinionated analysis of previous historiographical trends.  Secord makes an especially strong argument for setting the controversies surrounding Principles off to the side—its anti-Lamarckian stance, the uniformitarian versus catastrophism epochal debate—and remembering its almost universal acceptance as a soberly argued book that played a crucial role in making geology into a discipline.  We need more basic writing like Secord’s.  As strange as it may sound to call an intro to a Penguin edition of a primary source canonical, I can’t see this not qualifying.