Deep resistance to knowledge that betokens a change in a whole way of thinking has a long history. Think only of the horror displayed by the cardinals in Rome when Galileo discovered the moons of Jupiter with his amazing new tool, the telescope. The cardinals refused to even take a look. Galileo realized that Jupiter’s moons are circling Jupiter and that Venus is circling the sun, and so … crikey … probably Copernicus was right. Earth is also circling the sun—meaning that Earth is not the center of the universe. Not long after his announcement, Galileo was placed under house arrest and forced to recant his hypothesis that Earth revolves around the sun. His decision to recant had been influenced by his having been “shown the implements of torture.” So what was the big deal about Earth circling the sun? Every schoolchild learns that now and it does not stir up a hornet’s nest.
Why did the cardinals care so much? Did they “hate” Earth’s revolution about the sun? The general answer is that they cared because of what they believed about the physics of the universe. The conventional wisdom of the day assumed that Earth is at the center of the universe. Everything below the level of the moon is corruptible, changeable, earthly, imperfect. That is the realm of sublunar physics. Everything above the level of the moon is perfect, heavenly, unchanging, and so forth. This is the realm of supralunar physics. Different laws were thought to apply. The stars were widely thought to be holes in a huge sphere (literally made of crystal) that enclosed the universe—Earth at the center, of course. This cosmology was derived from biblical text.
Copernicus and Galileo threw that cosmology under the bus. The moons of Jupiter looked pretty much like our moon, meaning that they might be dirt balls, too. And so Jupiter might just be like Earth. But then, did God not create Earth at the center of the universe? Does this mean that the crystal sphere does not exist? But where, then, is heaven, if not just above the moon? Where did Jesus go when he ascended bodily into the sky? A specific, long-held worldview was fundamentally challenged, and the challenge generated fear of what might replace that worldview. The very institution of the Christian Church was founded on the belief in the bodily resurrection of Jesus into an actual place—heaven. And this actual place is above the moon, and maybe even above the stars. If you believe something to be absolutely certain and foundational, it is profoundly shocking to find that your “truth” may be mushy, or worse, quite likely false.
Think next of the impact of the discovery by the English scientist William Harvey in 1628 that the heart is actually a pump made of muscle. Consternation! Say it is not so! Not a mere meat pump! What was the big deal about the heart?
The conventional wisdom of Harvey’s time accepted a very different story that had been proposed by the Roman physician and philosopher Galen (129–199 CE). Galen’s idea was that being alive entails animal spirits vivifying the body. Where do the animal spirits come from? They are continuously made in the heart. That is the job of the heart—to concoct animal spirits. Vivifying? Means keeping alive. So it was a rather circular
and unhelpful explanation after all. In any case, the idea was that the animal spirits are continuously put into the blood by the heart, and the heart constantly makes new blood.
Harvey’s discovery that the heart is really a pump acknowledged that while a living animal is indeed different from a dead animal, spirits are probably not what make the difference. Blood is made somewhere else, and the heart merely circulates the blood.
Harvey’s colleagues were of course deeply steeped in the unquestioned “truth” of Galen’s account of animal spirits. Upon seeing Harvey’s data, they did in effect cry painfully, “I hate the heart, I hate the heart!” What was actually said was in a way worse. They said they would “rather err with Galen than proclaim the truth with Harvey.” This is the familiar strategy of let’s pretend. Let’s believe what we prefer to believe. But like the rejection of the discovery that Earth revolves around the sun, the let’s pretend strategy regarding the heart could not endure very long.
Why the anxiety about Harvey’s discovery that the heart is a pump? Because it was not merely the discovery of a little fact about an organ in your chest. For those alive in the seventeenth century, it challenged a whole framework of thinking about spirits and life that had been taken for granted as true since about 150 CE. It threatened the tight connection between the religious framework of life as a matter of spirits and the scientific framework that explored the nature of those very spirits. After Harvey, after Copernicus and Galileo, that connection ceased to be conveniently tight. Religion could either drop dogma and go with science, or religion and science would move apart.