Jefferson's Shadow

Keith Stewart Thomson (1938–2025) was a distinguished evolutionary biologist, historian, and writer. He was emeritus professor of natural history at the University of Oxford and had served as director of the Oxford Museum of Natural History, the Academy of Natural Sciences in Philadelphia, and the Peabody Museum at Yale University, where he was also a professor and dean. He wrote many books and essays on history, history of science, evolution, and paleontology, including The Common but Less Frequent Loon and Other Essays; Before Darwin: Reconciling God and Nature; The Young Charles Darwin; and The Legacy of the Mastodon: The Golden Age of Fossils in America.

“Architect, philosopher, critic of slavery, slave-owner; the contradictions of American ‘founding father’ Thomas Jefferson are well known. That he was a scientist is not. Natural historian Keith Thomson redresses the balance in this finely wrought biography.”—Nature“Thomson is most effective at explaining what is different or the same about eighteenth- or early nineteenth-century scientific knowledge and what we know now. He is able to make the present-day reader understand what was commonly known and what was novel about the conversations in which Jefferson took part.”—Susan Kern, author of The Jeffersons at Shadwell“An excellent book on a neglected topic, a fine addition to the existing literature, and a credit to Yale’s excellent eighteenth-century list.”—Frank Cogliano, University of Edinburgh“This is the most authoritative book published to date on the subject of Jefferson and science. It is comprehensive in its treatment of his wide range of scientific interests. It importantly demonstrates the depth of his knowledge and investigation, which were not amateurish or dilettantish.”—Andrew Jackson O’Shaughnessy, author of An Empire Divided: The American Revolutionand the British Caribbean and The Men Who Lost America“Keith Thomson’s engrossing, learned, and beautifully written new book offers a fresh portrait of the Sage of Monticello, showing how Jefferson found happiness in his scientific pursuits. Thomson illuminates the flaws and limits of Jefferson’s science, but the sympathetic image that emerges from Jefferson’s Shadow is one Jefferson himself would recognize.”—Peter S. Onuf, University of Virginia