A quick inspection of the “most famous historical couples” lists doesn’t offer many surprises. Though we may not know the details of their romantic lives, we’ve all heard of Anthony and Cleopatra, Napoleon and Josephine, Prince Edward and Wallis Simpson. No doubt David Bodanis was familiar with these couples when he was writing his book on Einstein, E=mc2, but he certainly hadn’t heard of the intense, 15-year love affair between Voltaire and Emilie du Chatelet, the wife of an obscure but wealthy Frenchman.

Nor had Bodanis come across a pairing that was as exciting—and as startling—as the one between Voltaire and du Chatelet. As Bodanis makes clear in his latest book, it was du Chatelet’s genius that inspired Voltaire to produce many of his best-known works. Perhaps even more importantly, du Chatelet published significant work of her own, including a brilliant translation of Newton’s Principia which helped usher in the French school of theoretical physics. Du Chatelet was little more than a footnote in E=mc2, but she was a footnote Bodanis couldn’t ignore. This is fortunate for readers, because it resulted in Passionate Minds, which offers an unforgettable portrait of two of the Enlightenment’s greatest minds.

Bodanis’s dual biography owes much of its readability to the remarkable personalities of du Chatelet and Voltaire. Emilie du Chatelet was not only a brilliant thinker – able to understand Newton’s dense equations and speak in multiple languages – she was also a woman who lived life exactly as she wanted to, or at least to the extent that she could in eighteenth-century France. Du Chatelet corresponded with the greatest mathematicians and scientists of her time, sending off book-length explanations of her ideas. She even secretly entered a paper on the nature of light in the illustrious French Academy’s competition, a work which received special mention and anticipated electromagnetic theory. As one mathematician remarked, “When you read [du Chatelet’s paper], you will find it hard to believe they gave the prize to anyone else.” Du Chatelet’s iconoclastic way of thinking extended to other areas of her life as well. Though Voltaire was the love of her life, he was not her first lover – nor her last. When she was in need of money, she would gamble to win what she needed — a feat which wasn’t too difficult for a woman who could count cards.

Voltaire cannot quite live up to du Chatelet’s larger-than-life personality, but he is an interesting character nonetheless. Best known for his play Candide, he is usually regarded as a great mind and not much more. Bodanis’s account gives us a much clearer, and at times less flattering, picture of Voltaire. Our first glimpse of him is as a young man about to be arrested for writing poetry critical of the king. As it turns out, he hadn’t even written the incendiary lines, but he was happy to take credit for them, sending the chief of police on a wild goose chase that led straight to his toilet—and ended with a broken sewer pipe that nearly incited a riot.

Voltaire’s attempts to prepare his entry for the French Academy prize are equally amusing. Whereas du Chatelet did most of her calculations in her head, Voltaire’s efforts were energetic, if misdirected. For weeks he threw himself into his scientific work, hiring glassblowers, ordering air pumps and thermometers, and even setting fire to small forests (with servants standing nearby with buckets of water). When his efforts did not produce the results he had hoped for he eventually returned to his truest talent: writing plays.

A biography of either figure would be more than satisfying, but what makes Passionate Minds: Emilie du Chatelet, Voltaire, and the Great Love Affair of the Enlightenment so compelling is the way Bodanis manages to capture the relationship between the two. Though his account of their first meeting contradicts other biographies, he vividly captures the impact each had on the other, quoting from poems, letters and diaries. At one point after their affair had ended, the two were traveling to Paris to retrieve books and papers necessary for Emilie’s translation of the Principia. Their carriage lost a wheel when they were still miles from their destination, forcing them to spend hours waiting to be rescued. Despite the fact that the ground was covered in deep snow and that Emilie was pregnant with another lover’s child, she and Voltaire wrapped themselves in furs and studied the vast canopy of stars above them. According to Voltaire’s servant, “I believe that only the fact that they lacked a telescope kept them from being perfectly happy.”

Biographies often sit on my bookshelves gathering dust before I get around to tackling them. Unlike fiction, I always read them at a steady pace over a period of weeks. Passionate Minds was a notable exception. It read like a thriller and was difficult to put down. Unfortunately I am not enough of an expert to comment on Bodanis’s aptitude as a historian. In researching du Chatelet’s and Voltaire’s lives – if Internet surfing can be considered “researching” – I did come across a few discrepancies. Which isn’t to say Bodanis’s account is inaccurate, but merely to renege myself from rendering a definitive judgment on this point. But what he does very well is to rescue du Chatelet and Voltaire’s love affair from the dustbin of obscurity where it has languished for more than two hundred years. He also gives us different, far more entertaining glimpse of the Enlightenment, complete with court intrigues at Versailles and midnight escapes from the king’s henchmen.