Science Isn't Just Common Sense

It surprises us—that's part of its charm.

Posted Jan 08, 2018

It is easy to think of science as essentially organized common sense, based as it is on generating hypotheses, testing them, evaluating the results of those tests, and then, if the findings are consistent (especially if they are coherent with a prior, unified body of theory) and if the predictions aren’t falsified over time, concluding that the results are scientifically meaningful, whereupon they are added to our body of knowledge. Science is a phenomenally powerful tool, the strongest and most effective yet devised. Contrary to widespread assumptions, however, science is most useful when its specific findings go counter to common sense. Indeed, science can usefully be conceived as a corrective to it. Otherwise, we wouldn’t need science; we could simply “go with our gut.”

Isaac Asimov (who was a highly regarded biochemist before he became a famous author) once noted science is “a way of trying to improve your knowledge of nature, it’s a system for testing your thoughts against the universe and seeing whether they match.” Often they don’t, and when that happens, it isn’t the universe that is wrong.

Intuition can be a misleading guide, even when it comes to something as seemingly cut and dried as physics. For example, it is tempting to assume—as did notable thinkers since Aristotle—that a heavy object would fall more rapidly than a light one. This was widely taken as a commonsensical “fact” until Galileo demonstrated that it isn’t true (although there is some doubt whether, as widely thought, he actually tested this by dropping two objects from the leaning tower of Pisa). Or take a ball on a string and swing it around in a circle. Now ask yourself: if you let it go while it is rotating, what path will it take? Many people—even college-educated science majors—assume that it would travel in a spiral. But it won’t. It will continue on a straight-line tangent to the circular route that it had been following.

There are many other cases in which what seems obvious is wrong. The sun doesn’t go around the Earth, as it appears to do. That same Earth isn’t flat, as it seems to be. Apparently solid objects are actually composed of mostly empty space. Science is a pushback against the errors that are frequently incorporated into what is often taken for granted. It is closer to the Enlightenment than to Romanticism, basing its insights on skeptical inquiry, data, analysis, interpretation, and debate rather than gut feelings, blind adherence to ancient texts (notably those reputed to be divinely inspired), or wishful thinking. It takes, after all, an outright denial of intuition to acknowledge that tiny organisms—much smaller than anything we can see with the unaided eye—can make us ill. Hence it is disturbingly easy for the antivaxer movement to gain adherents, even though being unvaccinated is immensely more dangerous than the alternative.

When Carl Sagan famously informed his television audience that we are all made of “star stuff,” the deeper implications may well have been lost on many of his fellow star-stuffed critters. Please meditate, for a moment, on the fact that there is literally nothing special about the atoms of which everyone is composed. Even in their statistical preponderance by mass, these elements reflect rather well the chemical composition of the universe as a whole: oxygen, carbon, hydrogen, nitrogen, calcium, and so forth. Of course, there is something special about the way these common components are arranged; that’s the work of natural selection, which, when presented with alternatives, multiplied and extended the frequency of those combinations that were comparatively successful in replicating themselves. All this, in turn, further highlights [CE1] the degree to which we are cut from the same cloth.

Recall Socrates’s dictum, “The unexamined life is not worth living.” The issue is not so much examining your own life, or human life generally, but rather, understanding both and doing so with humility, honesty, and an expanded sense of interconnectedness and potential. According to the King James version of the Bible, in 1 Corinthians 13:12, Paul wrote, “For now we see through a glass, darkly,” an observation that—suitably modified—led to the title of my next, forthcoming book. Paul went on to write that after this restricted, darkened field of vision, we could look forward, upon meeting God, to seeing “face to face,” adding, “now I know in part; but then shall I know even as also I am known.” Fine for believers, but for the secularists among us, there is even better news: through the glass of science, we can all know and be known, and see brightly, here and now.

Yet there is some wisdom in Paul’s “darkly,” namely that we don’t necessarily see the world with perfect accuracy. Why not? Because we haven’t evolved to do so. The fact that we can penetrate some of the universe’s deeper secrets, unravel our own DNA, and so forth, is remarkable, but not literally miraculous. Just as the human nose didn’t evolve to hold up eyeglasses, but does a good job at it, and binocular vision evolved to enable our arboreal primate ancestors to navigate their three-dimensional lives and has subsequently done a good job enabling us to throw objects accurately, drive cars, and pilot airplanes, our five senses along with our cognitive complexity and sophistication evolved for many possible reasons, including navigating an increasingly complex and sophisticated social life, engaging in elaborate communication skills, making and manipulating tools and other devices, predicting the future, and so forth.

Once it became part of our armamentarium, human intelligence and perception has underwritten all sorts of additional activities, such as exploring the universe as well as our own genome and composing symphonies and epic poems; the list is nearly endless, but the basic point is that we didn’t evolve with an explicit adaptive capacity to do these things. They were repurposed from neuronal structures and capabilities that emerged for other reasons, not unlike pedestrian curb cuts that have been engineered to permit wheelchair access from street to sidewalk, but are now used at least as much by bicyclists and skateboarders. The biological reality is that our perceived separateness may well have evolved so as to promote the success of our constituent genes, but at the same time, there was little or no evolutionary payoff in recognizing not so much our limitations as our lack thereof.

John Milton wrote Paradise Lost to “justify God’s ways to man.” In the end, what justifies science to men and women is something more valuable and, yes, even more poetic than Milton’s masterpiece or Paul’s vision: the opportunity to consume the fruits of our own continually reevaluated, deeply rooted, admittedly imperfect, and yet profoundly nourishing Tree of Scientific Knowledge, whereby we increasingly understand ourselves as we really are. I hope that most people will find more pleasure than pain in using science to do so, and in the process, seeing themselves and their species more accurately and honestly—more brightly, in every sense of that word—than ever before.