Though religious thought was key to early scientific breakthroughs, purists tend to erase this part of history. In his new book, What Galileo Saw: Imagining the Scientific Revolution, Lawrence Lipking reminds us of the real story.

"Contemporary enemies of science can all too easily appropriate the argument that scientific views are merely relative and contingent." That sentence appears, somewhat startlingly, near the conclusion of Lawrence Lipking's recently released What Galileo Saw: Imagining the Scientific Revolution. The sentiment itself isn't surprising; climate deniers, Christianists, and anti-vaxxers use any tactic they can to forward their views. But what's odd, in the context of the narrative, is labeling such people as "enemies of science." The bulk of Lipking's book is devoted to showing that the historical battle lines we tend to draw between science, religion, and art, aren't as bright and clear as we like to tell ourselves.

The pop culture account of science is, as Lipking, a Northwestern University emeritus professor of English, notes, one of continuous advancement and ever-clearer sight—or, alternately, one of ever-encroaching spiritual death, as cold technology alienates us from our true selves. But both narratives of progress and those of apocalypse erase the extent to which the scientific revolution was fired by religious fervor. Galileo, forced to recant his heliocentrism by the Church, nobly refused "to be swayed by myths or orthodoxies," and boldly declared, "Nevertheless it moves." Except, there's no record that he said that; the rejection of myths and orthodoxies is itself a myth—one of the founding stories of modernity's science code.

If Galileo saw the moons of Jupiter through his theory, didn't Newton see gravity through his God?

Along the same lines, Descartes’ famous mental experiment, in which he stripped the world down to what can be rationally known, was, it turns out, inspired by a series of vivid dreams, in which, Descartes believed, God had called him to a great work. Kepler introduced his epochal Third Law explaining planetary motion by declaring, "It is my pleasure to yield to inspired frenzy, it is my pleasure to taunt mortal men with the candid acknowledgement that I am stealing the golden vessels of the Egyptians to build a tabernacle to my God." As Lipking writes, "the brilliant mathematician in whose clockwork universe mankind still lives also pays homage to ancient wisdom and astrological charts."

The fact that the early scientific greats had numerous loopy ideas isn't usually seen as that much of a problem. Kepler’s record as both an astronomer and an astrologer can be dismissed with mutterings about the superstitions of the time. The astrology is jettisoned, and the pure science is preserved.

Disaggregating isn't necessarily always that easy, though. For example, Francesco Sizzi, one of Galileo's critics, looked through the spyglass too—and where Galileo saw the moons of Jupiter, Sizzi saw nothing. Was this because he had poor eyes, or a bad telescope? Maybe, Lipking writes, "students of vision have repeatedly demonstrated [that] seeing something involves the mind as well as the eyes." Based on what we know now about science, Sizzi failed to see because he lacked a theory that would put those moons into context.

Galileo, on the other hand, could see because he had the right theory. Evidence does not lead to theory; theory provides the context for evidence. Which means that Galileo's discoveries came not just from a dispassionate evaluation of what he saw, but from his imagination. And if he imagined those moons of Jupiter, are we still imagining them with him?

Philosopher of science Paul Feyerabend notoriously took this kind of reasoning and used it to question the entire scientific program—to argue that there is no categorical distinction between the "correct" scientific worldview (the Earth goes around the sun) and the alternate, "incorrect" ones, except for current fashion and institutional authority. Feyerabend argued that there was no real reason at the time to believe that the telescope showed an accurate view of the heavens; Galileo's theories were based not on truth but on ad hoc guesses and leaps of faith—as Feyerabend argues, all science.

Lipking steps daintily around that particular gravitational pit; when he discusses Newton's millenarian religious musings, for example, he is careful to note that the scientist's breakthroughs "depended on meticulous calculations, not magical thinking." But the pit still yawns off to the side distractingly. What after all do we mean by "depended"? Newton's intellectual pursuits were inspired by his religious beliefs, and arguably vice versa. If Galileo saw the moons of Jupiter through his theory, didn't Newton see gravity through his God? And if so, is the gravity there without the God?

The skepticism there may seem silly or excessive. Of course we know that Newton's gravity works. But then, don't we also in fact know, via Einstein, that Newton's gravity does not work? And how sure are we about Einstein's? Likpking points out that one of the most important engines of the Scientific Revolution was skepticism—the willingness to question received wisdom, the recognition that authority could not be a guarantor of truth. But as Lipking writes, "this unsheathed skepticism" is "a two-edged sword." Once you start questioning, where do you stop?

That's why those enemies of science often come across not as anti-science, but as hyped-up, manic, science on steroids. No one can site as many statistics as an anti-vaxxer; no one is more doubtful or more demanding of evidence than a climate denier or creationist. It isn't that these groups reject science, but that they take its skepticism too far, refusing the established, scientific consensus—rather like Galileo. The weapons of reason ultimately turn back on reason, until all certainty is voided, and we don't know whether Galileo said "it moves," or whether Newton understood gravity.

You could see this uncertainty as a failure of science; mixing astrology with your astronomy, or theory with your moons, or God with your machine might be taken as a loss to all those lurking enemies of reason and truth. But that seems overly defensive. We don't, or at least shouldn't, expect universal truth from, or universal acquiescence to, any of our dreams, whether it’s religion, philosophy, or art, to the extent any of those can be separated.

In fact, one of Lipking's achievements is to put science in the context not just of religion, but of art and poetry. Part of the reason Galileo's ideas were so seductive was because he was an artist, who could express what he saw, and what he thought he saw, on paper for others to see. Science, in Lipking's telling, is not opposed to imagination. "Imagination validated science, in this new world; and science imagination," Lipking concludes. And that new world is still, in a lot of ways, the world we're living in, though the habit of imagining through science is so ingrained now that we sometimes miss the wonder of it. Galileo saw the Earth spinning around the sun, and we still see with his eyes and dream with his dreams.