[I’m posting this now, but read the book 9/2007].

Passionate Minds (2006) is a dual biography of Voltaire (1694-1778) and Emilie du Chatelet (1706-1749). They met in 1733, when Emilie was 27 (and Voltaire was 39). This was an enjoyable and informative book, especially since I had never heard of Emilie du Chatelet (and only a passing knowledge of Voltaire). While the book does read something like a romance novel, there is enough substance to keep your attention.

Emilie was married at the time she met Voltaire, but that didn’t stop them from having a very passionate affair. This, it turns out, was a fairly common thing to happen, and people looked the other way as long as they were discrete. Emilie’s husband also had a mistress, so things evened out. :)

Emilie was a brilliant woman, and she was translating (and understanding) Newton’s Principia. Voltaire was just a poet. Anyway, they had a very real “meeting of the minds” and Emilie could more than hold her own with Voltaire’s intellect.

The story of their 15-year relationship is great reading. It was fascinating to get a glimpse of the intrigue, etc. of France at the time (the French Revolution was after this, in 1789). One great story is how Voltaire and Emilie turned a rural chateau at Cirey into their own laboratory. They used it as a place to conduct experiments and write, and they were inseparable. They had created a space where they could think for themselves, with one supporting the other. They collaborated on a book, “The Principles of Newton”, which was a study of Newton’s “Principia Mathematica”.

Emilie was fluent in Latin and understood the mathematics (she explained the math to Voltaire, but he didn’t really get all of it). They actually setup and performed the experiments that Newton had described. “Principles of Newton” was published with only Voltaire’s name, but everyone knew of Emilie’s contribution (she was in correspondence with most of the great mathematicians of the day).

Emilie, on her own, completed a translation of the Principia – with commentary. It was the commentary that was fundamental to further developments of 18th century physics. She finished the manuscript while pregnant (with the child of a much younger man who subsequently dumped her). Emilie died a week or so after giving birth, at the age of 43. Voltaire lived with her at the end, and he lived on to be 84.