Stephen Case, <i>Creatures of Reason: John Herschel and the Invention of Science</i> Pittsburgh: University of Pittsburgh Press, 2024. Pp. 320. ISBN 978-0-8229-4838-4. $55.00 (hardcover).

Approaching Stephen Case's second book, Creatures of Reason, through the lens of scientific biography would be a natural impulse, but, I think, a mistaken one.What we have here is the history of an episode in the development of science as a category, a narrative with two central characters.One, familiar from Case's other work, is Sir John F. W. Herschel (1792-1871), son of William Herschel (1738-1822), discoverer of Uranus, and nephew of Caroline Herschel (1750-1848), one of the most adept analysts of astronomical data of her day.But there is a second main character in this story: the book for which Herschel would be best known in his own day, and which still garners the lion's share of his fame (especially in the philosophical community): A Preliminary Discourse on the Study of Natural Philosophy (1830).Published in Lardner's Cabinet Cyclopaedia series, it marked a crucial moment in the scientific formation of a cast of characters, from Charles Darwin, to Michael Faraday, to countless everyday readers who approached the work as something like a crash course in the virtues that should be possessed by any rational, truly scientific thinker.Case's book, then, is the story of how Herschel became the person who was capable of writing the Preliminary Discourse.Although, to be sure, this gives it many commonalities with a scientific biography, it only covers the first forty years or so of Herschel's life, stopping just at Herschel's voyage to the Cape of Good Hope, prior to his full role in the invention of photography, before his days administering the Royal Mint.Perhaps the book's most remarkable feature is what it does not have.One might be worried that, in orienting the book entirely toward the yet-to-occur publication of the Preliminary Discourse, Case's history of Herschel's life would be too Whiggish, a kind of teleological presentation of the steps that inexorably led to his magnum opus.But it is just here that I found the book particularly impressive.For, as Case clearly demonstrates in this delightfully readable volume, the Preliminary Discourse arose directly from the vast array of experiences which Herschel lived from his earliest days attempting to reform mathematics education at Cambridge.His time studying law (along with the chemistry experiments he would perform on the side), his work in building the Astronomical Society, his constant skirmishes with fellow reform-minded scholars against the slow-moving Royal Society, his several trips across the European continent building a research network (and being exposed to superior forms, he thought, of scientific work and governance), his marriage to the devoutly religious Margaret Brodie Stewart (1810-84), his expansion and eventual completion of his father's astronomical survey programme -all of these influences can be, Case deftly argues, more or less directly read from the pages of the book that would result from this period of his life.