The Organs of Sense by Adam Ehrlich Sachs

In an account sent to the Philosophical Transactions but for some reason never published there, or anywhere else, a young G. W. Leibniz, who throughout his life was an assiduous inquirer into miracles and other aberrations of nature, related the odd and troubling encounter he had with a certain astronomer who'd predicted that at noon on the last day of July 1666, the brightest time of day at nearly the brightest time of year, the Moon would pass very briefly, but very precisely, between the Sun and the Earth, casting all of Europe for one instant in absolute darkness, "a darkness without equal in our history, but lasting no longer than four seconds," the astronomer in Europe was predicting, according to Leibniz, an eclipse that no other astronomer in Europe was predicting, and which, Leibniz explained, drew his notice in part because the astronomer in question, whose observations of the planets and the fixed stars were supposedly among the most accurate and the most precise ever made, superior to Tycho's, was blind, and "not merely completely blind," Leibniz wrote (in my translation from the Latin), "but in fact entirely without eyes."

When Leibniz, the mathematician and philosopher probably most famous for A.) being one of two people to invent calculus, and B.) getting his ass handed to him by Voltaire, goes to visit the blind astronomer who claims to have predicted an eclipse without the use of his eyes, he is drawn into questions of sanity and madness as much as questions of astronomy. Leibniz arrives on the day of the supposed eclipse, knowing that if the eclipse doesn't happen, the astronomer will be proven insane (though if it does, he won't necessarily be proven sane--I think I'm getting that right), and while he waits, the astronomer tells him a remarkable shaggy dog story, ostensibly about how his eyes got torn out.

The story of how he got his eyes torn out, the astronomer explains, is the story of his life, and so he starts from the beginning: as the son of the former sculptor to the Holy Roman Emperor, who hopes to get his job back by creating a totally lifelike but mechanical human head. The son overshadows his father by inventing the telescope on the spot, allowing the Emperor to see a new star that has recently appeared in the European sky, and becomes the Empire's official astronomer. In this position he's drawn into the intrigue of the Emperor's family, including the heir to the throne, a dangerous murderer who himself may or may not be sane. A perilous success in the palace grants him total freedom--and unlimited telescopes--to map the heavens from his lonely observatory, where Leibniz has met him. This story unfolds over the course of three hours, moving toward its climax--the moment of the eye-obliterating--at the exact moment of the supposed eclipse.

What The Organs of Sense captures so well, I think, is a moment in the history of science at which knowledge about the cosmos was blooming at the same time that doubts began to fester about our ability to see and understand the world. At the same time that Kepler and other astronomers, like the one in the novel, were mapping stars and explaining the motions of the planets, philosophers like Descartes were wondering if the mind can ever really know anything but itself. Leibniz is obsessed with questions of madness because a world in which no one can really see outside of themselves is one that does away with distinctions like sane and insane; to understand the cosmos above one's head must also be to understand the cosmos within one's head. But Cartesian dualism shakes the core of this: consider the "insane" Prince, who has come to believe that only he exists, and that everyone else in the world is a mechanical automaton who speaks his own thoughts back to him. And what should Leibniz make of the blind astronomer, without access to the world, who yet claims to predict its movements?

I expected The Organs of Sense to be something like Labatut's scientific-historical fiction book When We Cease to Understand the World, perhaps not least because there is a kind of historical rhyming in the destabilizing effects of Cartesian dualism and that of twentieth century quantum mechanics. But Sachs' novel is something more like Borges or Calvino; a fable, or a picaresque, colored with humor. The layered narrators--the astronomer, Leibniz, the unnamed translator--give the whole thing a kind of specious hearsay quality that strengthens the themes. And most importantly, The Organs of Sense sticks the landing. I don't know if I've just been reading a bunch of books that fumble the ending or what, but the way the whole thing comes together--and especially the resolution to the question Leibniz waits hours for, how does he see the cosmos without eyes--is tremendously satisfying.