Science coexists with society. Science shapes society, informs society, enables society to function in ways not possible without an in-depth knowledge of how the natural world works. But you can flip that coin and declare, equally accurately, that society shapes science. Science responds to societal needs, reflects societal values, conceives of nature within the framework of society’s prevailing worldview. And science thrives only in societies where knowledge and reason are not overwhelmed by superstition and prejudice.

So modern science, the conventional story says, emerged with the societal Renaissance that ended the millennium-long “dark” ages. A rebirth of learning transformed society from medieval to modern, enabling the birth of modern science.

“There can be no doubt,” science historian David Lindberg has written, “that in the early modern period science found itself in new social circumstances, which influenced its practice and altered its shape.”

Thanks to this synergistic coexistence, modern science and modern society have achieved heights of sophistication, complexity and affluence far beyond the dreams of medieval savants. Society enjoys the fruits of labor-saving machinery, electronic technological wizardry, health care expertise and agricultural and industrial productivity that science has made possible. At the same time societal support has allowed modern science to master the microworld of atoms and molecules, the vastness of the cosmos, the secrets of stars and planets, the mysteries of the Earth’s environs and its innards, the mechanisms of life and the origin of its multiplicity of species — not to mention the architecture of the human body and brain. Modern society, and modern science, could not be more different from their medieval predecessors.

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But then again, in some ways both science and society have remained very much the same. Society still embraces superstitions and prejudices. Greed, corruption and violence do not seem to be in any danger of disappearing. And modern science, for all its progress and achievements, has not resolved many of the issues that arose in medieval times. In many, many ways, modern science retains a medieval mentality, by which I mean a frame of mind mired in deep physical, philosophical and technical problems that impede the path to a profound and indisputable grasp on truth.

Nobody denies that science has made enormous progress in comprehending nature, or that today’s best theories and analytical tools far exceed the scope and explanatory power of medieval beliefs and methods. Yet deep questions remain unsolved, and scientists today struggle with issues very similar to those that occupied the best medieval minds.

For instance:

In medieval times, Europeans learned the view of the ancient Greeks that “celestial” matter in the heavens differed in nature from matter making up the Earth. Today, scientists have concluded that the bulk of cosmic matter is indeed unlike anything known on Earth, but have been unable to determine just what that cosmic matter is made of. Medieval thinkers similarly debated about the properties of celestial matter — whether it was crystalline and rigid or fluid, for example.

Medieval scientists (natural philosophers) also wondered whether the universe is eternal or had a beginning. Aristotle had argued strongly for eternal. Medieval authors debated that point in light of the Christian creation story. Today physicists generally believe in a Big Bang creation of our universe, but also debate whether the popular theory explaining that event — inflation — implies a preexisting universe extending back eternally.

Medieval scientists argued about the proper methods for establishing scientific truth, debating the role of observation and reason and the proper use of experiments. Today methodology debates are much more sophisticated, but the proper way to design and evaluate experiments — and draw correct inferences — remains a source of vigorous discussion among scientists and philosophers alike.

Other questions can be posed in both the medieval and modern context. Can a void exist beyond the universe we inhabit? Again, Aristotle said no, but medieval scientists often argued otherwise. Today some physicists picture the universe’s three space dimensions as occupying an empty “bulk” space of higher dimensions. Consensus on this point is as elusive today as it was seven centuries ago.

Are there multiple universes, or only one? The medieval worldview encompassed one cosmos: a set of nested spheres, self-enclosed by the outermost one. But many natural philosophers and church officials alike contended that God could very well have decided to make other worlds. And today cosmologists seriously consider the possibility that our universe is just one in a multitude of spacetime bubbles — a multiverse — beyond our immediate awareness.

More generally, medieval experts debated whether science should restrict itself to direct experience or could consider factors abstracted from experience by reason. Averroës, a medieval Muslim philosopher, “identified the real world with the directly observable and concrete,” the historian A.C. Crombie wrote (a view shared by William of Ockham, famous for his “razor”). But while Averroës argued that abstract concepts were imposed on nature by modes of human thought, others, such as Avempace, believed that a deeper reality was revealed by the idealizations that reason could draw from direct experience. Much the same argument is alive in science today. Some scientists complain that a multiplex of unseen universes, or “superstrings” too tiny to detect, are not scientific at all, while others vigorously pursue those topics as mainstream scientific research programs.

On a related point, scientists then and now have both grappled with the nature of mathematics and its relationship to physical reality. Medieval scholars adopted Claudius Ptolemy’s mathematical treatment of planets circling the Earth, orbiting along circles modified by epicycles. But Ptolemy’s system was meant to be a method for predicting the motions of points of light in the sky using math. He wrote an entirely different book to discuss the nature of the planets’ physical reality. The more general issue was whether math is just useful for predicting observations (“saving the phenomena,” as medieval writers called it) or if it inheres directly in physical reality (as the ancient Pythagoreans, and Plato, believed). This issue resonates today in debates about the quantum wave function. It’s a mathematical expression that excels for making predictions of experimental outcomes. But experts don’t agree on whether it is “ontic” — possessing a reality of its own — or “epistemic” — merely offering knowledge about a system that is useful for predicting its behavior.

Other medieval-modern similarities arise when a science’s implications elicit objections to its validity. Despite the popularity of astrology in medieval times, some thinkers objected to it on the grounds that celestial control of personal destiny eliminated human choice and free will. Many medieval philosophers sided with St. Augustine, who had written that “the choices of the will are not subject to the positions of the stars.” Much the same sort of dispute over science occurs today about how findings from neuroscience could imply lack of free choice in human behavior.

Medieval scientists also argued about the proper methods for establishing scientific truth, debating the role of observation and reason and the proper use of experiments. Today methodology debates are much more sophisticated, but the proper way to design and evaluate experiments — and draw correct inferences — remains a source of vigorous discussion among scientists and philosophers alike.

Now, the point of all this is not that science has made no progress since the days of Averroës or William of Ockham. Or to just have fun finding some medieval-modern analogies. Rather the point is that the generalized system of science, for seeking truth about the workings of the natural world, is in a sense still medieval — that is, a prelude to a deeper understanding that may not come for another millennium.

Science’s history suggests that some of the grandiose claims of modern science’s success should be tempered by an appreciation of how it is likely to be viewed in the future. A few centuries from now, today’s grand scientific edifice will no doubt be viewed as something like a medieval cathedral — magnificent, to be sure, but nevertheless a product of a backward intellectual age. Some problems that perplex scientists today will have been solved; other questions viewed as crucial today will be seen as insignificant or improperly posed; topics not yet imagined today will be textbooks trivialities then. But even half a millennium from now, it may still well be that the deepest questions about reality and existence, mathematics and physics, eternity and ultimate truth, will still be fodder for bloggers whining about what science still doesn’t know.

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