Stephen Snobelen
 on February 09, 2017

The Myth of the "Medieval Gap"

By drawing attention to the Myth of the Medieval Gap and other fantasies, Carl Sagan probably did more (unintentionally) to advance historical fiction than anyone since Andrew Dickson White.


In September 1980, a thirteen-part TV series called “Cosmos: A Personal Voyage” debuted on PBS stations across the United States. Written by the late Carl Sagan, his soon-to-be wife Ann Druyan, and his former student Steven Soter, it brought Sagan and his sonorous voice worldwide fame. The companion book has also been hugely popular, selling more than five million copies. By drawing attention to the Myth of the Medieval Gap and other fantasies, Sagan probably did more (unintentionally) to advance historical fiction than anyone since Andrew Dickson White. (image of the first edition from Amazon)

If there is a fundamental conflict between science and religion—especially between science and Christianity—then a period during which Christianity was the dominant cultural force should be characterised by a stagnation, decline or even absence of science. As we saw in a previous column, there is no essential conflict between science and religion; instead, there is some harmony, some dialogue, some independence and some conflict. Some of this is localised conflict and some is constructed for rhetorical and political purposes.

However, another implicit essentialism accompanies this belief—namely, that something called “science” already existed prior to the beginning of Christianity and re-emerged only after Christianity’s influence began to abate. For those who hold the Conflict Thesis, it is axiomatic that science existed in Ancient Greece, only to languish and retreat during the Middle Ages. This is the Myth of the Medieval Gap, in which ideology is applied to history. Although there is a hefty dose of a priori thinking in all of this, the myth also rests in part on a common intuition that the Middle Ages were characterised by ignorance and backwardness. Of course, the term ‘Medieval’ is often used as a pejorative to describe ignorance and backwardness—and as a way for us to bask in our own enlightened state. It’s no accident that Andrew Dickson White actually used that word in exactly this way. The widespread belief that this period was characterised by ignorance helps explain why so many simply take it for granted that Medieval people believed in a flat Earth. Yet this idea is also a myth, even though Neil deGrasse Tyson tweeted it (and was quickly corrected by his followers), Commander Riker and Captain Picard mentioned it in Star Trek: The Next Generation, and former President Barack Obama alluded to it in a speech about climate change. So, too, is the common belief that the Catholic Church prohibited human dissection in this period, despite the efforts of Harvard historian Katharine Park to debunk it.

What do the specialist historians say about science during the Middle Ages? First, it is only with significant qualifications that we can say science existed in Ancient Greece. To say that there is something identifiable as “science” and people identifiable as “scientists” in Ancient Greece is to think in ahistorical rational reconstructionist terms (I’ll return to this in a future column). Second, insofar as we can speak of Greek science, it was already in decline before Christianity came to political power. Third, while it is true that the first half of the Middle Ages did not enjoy the intellectual vibrancy of the second half, this can be explained in large part by various pivotal historical contingencies, not the least of which were the highly disruptive Barbarian invasions. Nevertheless, in most historical periods the second half usually enjoys more advances, including those in science and technology. This is true of the Early Modern Period, the nineteenth century, the twentieth century and (if we survive) will likely be true of the twenty-first as well. Fourth, there was a great deal of innovation in science and technology in the second half of the Middle Ages on the part of Christian and Muslim philosophers—so much so, in fact, that by the end of the Medieval period, science and technology had reached a state of sophistication and refinement that far surpassed that of the Greeks. Not bad for a bunch of Medievals.

The innovations and inventions of the Middle Ages are too diverse and numerous to list here; a few will have to suffice. Universities emerged starting in the eleventh century and their curricula included subjects we would now include in the sciences, including geometry and astronomy. Nothing as grand as Gothic architecture (which began in the twelfth century) could be accomplished in the Ancient Greco-Roman world. The Voyages of Discovery began in the Middle Ages, starting with the Irish and the Vikings. Medieval Europe gave us the horse collar, the rudder, eye glasses, buttons, trousers, the fork, windmills and the mechanical escapement clock. The printing press was a late Medieval invention. Medieval Europeans also benefited from innovations from outside Europe that the Greeks and Romans did not possess, including paper, gunpowder, the compass and the Hindu-Arabic numeral system. (See Chiara Frugoni, Inventions of the Middle Ages; Frances and Joseph Gies, Cathedral, Forge and Waterwheel; and Jeffrey R. Wigelsworth, Science and Technology in Medieval European Life.) Islamic civilisation brought innovations in mathematics, astronomy, optics and other fields to Europe that the Greeks were centuries too early to experience. Yes, these were from outside Christianity, but it demonstrates that the history of science has a good deal of contingency and that any idea that something like modern science would have continued to develop among the Greeks is far too simplistic. The Myth of the Medieval Gap also shunts aside substantial innovations in the practice and theory of science, including the contributions of Robert Grosseteste (a Catholic bishop) and Roger Bacon (a Franciscan) to the empirical method, William of Ockham’s “Razor” (the parsimony principle), and the impetus theory of Jean Buridan. Another important fact usually left out by proponents of the Medieval Gap is the invention of the Cyrillic script (the basis of several alphabets) during the so-called “Dark Ages” by Christian missionaries, thus setting these cultures on the road to literacy.

Those who argue that Christian Europe suppressed science fail to ask just how Christian Europe actually was at various points in the Middle Ages. In fact, Europe wasn’t fully Christianised until the early modern period, when part of northern Scandinavia became Lutheran. Large parts of Europe, especially in the north, remained pagan. The Iberian peninsula became a Muslim territory in the eighth century, and parts remained thus until the fall of Grenada in 1492. Those who promote the idea that the Middle Ages was a scientific backwater make much of the apparent correlation between the spread of Christianity and the relative lack of scientific and technological innovation at the beginning of that period, which lasted roughly 1000 years. What they fail to realize is the impact of Barbarian Invasions and political dislocations.

But, if we play the correlation-equals-causation game (which is a fallacy to begin with), then this argument proves more than advocates of the Medieval Gap want. For instance, there is a common assumption that Europe in the Middle Ages and the Early Modern Period was a cultural monolith dominated by the Church. This can hardly be said of the first half of the Middle Ages. Yet, it was only when the Catholic Church had consolidated its power in the second half of the period that there was a relative flourishing of science and technology. More spectacularly, it was precisely the period when Europe was at its most Christian—the sixteenth and seventeenth centuries—that science as we now know it emerged. (I am not saying that Christianity was in any simple way responsible for the emergence of modern science, only that the correlation argument can come back to bite its proponents).

In sum, the Myth of the Medieval Gap has a surface plausibility, not only because the first half of the Middle Ages was relatively bereft of scientific innovation—giving this myth, like many other myths, some basis in reality—but also because it exaggerates the achievements of Greek Science and downplays the achievements  of the Middle Ages, especially in the area of technology. Much of its traction comes without much intellectual effort, because it rests on the pre-existing, essentialistic (but culturally widespread) notion that science and religion are necessarily in conflict with each other. Yes, one can find some examples of hostility towards some aspects of Greek learning in the early history of the Church; Tertullian would be a prime example. However, the hostility was mostly directed against Greek philosophy generally, not against what we would call science today.  At the same time, one can also find many examples of Christian clergy who held a generally positive attitude towards Greek philosophy, such as Clement of Alexandria. Even in figures like Augustine, we find deep respect for astronomy—something much closer to modern science than many other parts of Greek philosophy. Sound and well-documented rebuttals of the Medieval Gap are available and easily accessible (see the references below). It is thus surprising that the myth is still actively promoted by some very well educated people.

Carl Sagan as Myth-Maker

Carl Sagan’s justly celebrated 1980 television series Cosmos is one of the most successful and popular science documentaries ever produced. Its thirteen episodes provide a tour of both science and the universe, and Sagan’s enthusiasm for science and discovery is palpable throughout. I use this series in a course I teach on science and the media as an example of a science documentary done right. This is not to say that it is without defects. A religious viewer will likely find Sagan’s more overt criticisms of religion (especially Christianity) grating, even while atheist viewers would likely applaud. But these elements are more subjective. There are other elements where Sagan unquestionably gets his history wrong. Perhaps the most egregious example is the infamous white space in his timeline of science and technology from the companion book to the series: see the image at right. Here, Sagan places some of the heroes of Greek science: ThalesPythagorasPlatoPtolemy. This is followed by a note beside the early 400s that reads: “Destruction of Alexandrian Library, death of Hypatia, onset of ‘Dark Ages’.” Then comes a large white space that is finally interrupted with the names Columbus, Leonardo and Copernicus clustered around the year 1500. A telling note at the bottom of the timeline reads: “The millennium gap in the middle of the diagram represents a poignant lost opportunity for the human species.” The intended meaning is clear, even though the cluster of names around and immediately after the years 1500 are those of Christians (including KeplerHuygens and Newton).

RIGHT: This diagram, from p. 335 in the 1982 edition of Carl Sagan’s Cosmos, depicts his historically impoverished understanding of the Middle Ages. Photograph by Stephen Snobelen.

In his book and television series, Sagan portrays the Alexandrian philosopher Hypatia as a martyr of science who died at the hands of fanatical, anti-intellectualist Christians. The implication is that the violent death of this woman is a potent symbol of the anti-scientific ethos of Christianity. Yet, as a neo-Platonist, Hypatia was much more of a religious mystic and even a proto-monotheist than a proto-atheist or atheist—as she is incorrectly insinuated to be in the 2009 film, Agora. (For incisive commentary on the many major inaccuracies in this film by atheist blogger Tim O’Neill, see this and this.) The Library of Alexandria formed part of the Museum of Alexandria. It was founded as a temple to the Muses, was headed by a priest, and functioned as a religious shrine as well as a centre of learning (Lindberg, The Beginnings of Western Science, p. 72 ). Sagan’s book implies that the library was destroyed by Christians after the death of Hypatia, but the original library (the Great Library) was in fact long since gone by this time—first devastated by a fire caused by Julius Caesar’s troops in 48 BC and thereafter through a gradual decline. Even the daughter library was likely no more at this point, since it had been housed in the Serapeum, which was destroyed in 391, and there is no evidence that the Serapeum held the library at this late date. And, Hypatia’s death had more to do with politics than religion.

Sagan’s Cosmos reinforced both the Medieval Gap and the anti-Christian account of Hypatia’s death in popular culture. But this is myth-making, not history. The only real gap here is in Sagan’s knowledge of the history of science.


Biologist Jerry Coyne is just one of several New Atheist authors who tend to ignore the many scientific achievements of Medieval and Early Modern Christians. He dismisses those (numerous) historians who believe that Christianity contributed significantly to the rise of modern science as “accommodationists,” a term he has also hurled pejoratively at many secular scholars who do not share his very low view of religion—including such luminaries as Ronald NumbersMichael Ruse, and Elliot Sober, none of whom believe in God. Sadly, many people unthinkingly accept the baseless historical opinions of anti-religious scientists like Coyne (or Steven Weinberg), rather than those of historians and other scholars who have actually published peer-reviewed research on the topic. 

Carl Sagan was hardly the only modern author to promote the Myth of the Medieval Gap as a way to advance an anti-religious agenda. In 2013, biologist Jerry Coyne did likewise, in response to the claim that Christianity helped encourage the rise of modern science—a point made by many respected historians, including Stephen Gaukroger, whom he quotes. Coyne lists a series of objections, including the following: “Christianity was around for a millennium without much science being done; ‘modern’ science really started as a going concern in the 17th century. Why did it take so long if Christianity was so important in fostering science?” Then, in his conclusion, Coyne speculates, “I maintain, though I can’t prove this, that had there been no Christianity, if after the fall of Rome atheism had pervaded the Western world, science would have developed earlier and be far more advanced than it is now.” In his 2015 book Faith vs. Fact, Coyne concedes that religion and Christianity have made contributions to science, but he embraces aspects of the Medieval Gap when he criticises the argument that Christianity gave birth to science (see pp. 211-17, with concession on p. 217).

The late Victor Stenger, too, has a mixed record on the Medieval Gap. In a podcast debate with philosopher of science Steve Fuller, towards the end Stenger made some rash claims about the history of science, including the claim that atheism “has helped a lot of scientists from being burned at the stake,” when in fact none ever were. As he goes on to say, “we had science 2500 years ago … we went through a period of Dark Ages where we lost it. And what was the cause of the Dark Ages? Christianity. And then when Christianity finally began to be chipped away at in the Enlightenment, we got science back!”

At this point, Steve Fuller interjected and correctly pointed out that the Scientific Revolution happened one hundred years prior to the Enlightenment and noted the preponderance of Protestants involved in it. However, Stenger offers a more measured account of Medieval science in his book God and the Folly of Faith (2012). His account of this period in the third chapter contains much that is historically accurate, and he concedes that the “Dark Ages” were not entirely dark, although the tone is still set by the chapter’s title, “The rebirth and triumph of science,” which alludes to the idea that the Greeks had science, but that it was lost during the “Dark Ages.”

Another prominent advocate of this myth is British philosopher A. C. Grayling. In an opinion piece published in The Guardian, Grayling wrote:

“Seven centuries after the beginnings of classical civilisation in the Greece of Pericles and Socrates, an oriental superstition, consisting of an amalgam of dying and resurrecting god myths and myths about the impregnation of mortal maids by deities, captured the Roman Empire. Such was the beginning of Christianity. By the accident of its being the myth chosen by Constantine for his purposes, it plunged Europe into the dark ages for the next thousand years—scarcely any literature or philosophy, and the forgetting of the arts and crafts of classical civilisation (quite literally a return to daub and wattle because the engineering required for towers and domes was lost), before a struggle to escape the church’s narrow ignorance and oppression saw the rebirth of classical learning, and its ethos of inquiry and autonomy, in the Renaissance.”

Scarcely any literature or philosophy? Scholars of Medieval thought will protest this quick and easy dismissal of their fields. And what of science? Grayling appears unaware (or unable to acknowledge) that the fields of physics, cosmology, astronomy and optics (to name just a few) reached a higher level of development by the end of the Middle Ages than they ever did during Classical Antiquity, as great as the intellectual achievements of the ancient Greeks were.

But even Grayling’s claims seem moderate and temperate compared to those of David Mills, author of Atheist Universe (2004), a bestseller on Amazon. Mills’s passionate enthusiasm for the Medieval Gap appears to get the better of him, starting with this claim (p. 48): “For 1500 years, the Christian Church systematically operated torture chambers throughout Europe. Torture was the rule, not the exception. … Each year, the Christian Church in Europe tortured to death tens of thousands of people, including children as young as two years of age.”

Certainly many people were “tortured to death” by Medieval Christians, but this is a wildly exaggerated statement. Twenty thousand deaths per annum (to take his number at face value) makes a total of 30,000,000 deaths for the stated period of 1500 years. Scholarly estimates for the number of witches put to death range from 7000 to 100,000 deaths for the entire Middle Ages and Early Modern Period combined. The number of people executed for heresy during the same periods is much lower. The fact that there were political, social and cultural dynamics (as well as religious motivations) behind such deaths helps explain, but does not justify, these actions. Nevertheless, the number of deaths is far, far lower than Mills’ gratuitous, reckless and undocumented estimates—which promote misinformation and (ironically) intolerance. The moral: when one is on the side of the angels, one does not need to check facts. Mills conveniently ignores the suffering of Christians at the hands of imperial Rome and, more recently, the officially atheist communist countries. His book includes a foreword by Dorion Sagan, son of Carl Sagan, and Richard Dawkins’ endorsement on the front cover of the current paperback edition reads, “An admirable work,” an assessment first offered in The God Delusion (p. 44). But Dawkins is not a historian.

Mills also believes that Christianity is an inveterate opponent of scientific progress:

“Aside from the wholesale extermination of ‘witches,’ the Christian Church fought bitterly throughout its history—and is still fighting today—to impede scientific progress. Galileo, remember, was nearly put to death by the Church for constructing his telescope and discovering the moons of Jupiter. For centuries, moreover, the Church forbade the dissection of a human cadaver, calling it ‘a desecration of the temple of the Holy Ghost.’ Medical research was thereby stalled for almost a thousand years. It is no coincidence, therefore, that Christianity’s longest period of sustained growth and influence occurred during what historians refer to as the Dark Ages.” (pp. 48–9)

Every sentence in this passage contains at least one fundamental historical error, but here I note only that “Dark Ages” is not a term many professional historians would endorse.

Now, I want to be fair here. It is not all as bad as this. Some of it is a lot worse. Mills goes on wistfully to imagine the achievements science could have made early on, had it not been for the stifling effects of Christianity:

“Fifteen-hundred years of progress were therefore stifled by the Christian Church. Were it not for religious persecution and oppression of science, mankind might have landed on the moon in the year A.D. 650. Cancer may have been eradicated forever by the year A.D. 800. And heart disease may, today, be unknown. But Christianity put into deep hibernation Greek and Egyptian scientific gains of the past.” (p. 49)

Mills displays a blithe disregard for historical contingency and seems to think that scientific ideas are objects merely waiting to be discovered and that they develop simply according to their own internal logic—provided that there are no checks in place to hold them back. Similar thinking appears to be behind the 2009 film Agora, which portrays the early fifth-century mathematician Hypatia as discovering the elliptical orbits of planets, which were not actually discovered until the early seventeenth century by Johannes Kepler. The idea seems to be that, except for the one-thousand years or more of the Christian non-scientific interregnum, the Greeks would have quickly progressed to elliptical orbits and Newton’s Inverse-Square Law.

Something like Mills’ argument for a gap in scientific progress is seen in a chart (below) of “Scientific Achievement,” from a 2007 article by an atheist known as Jim Walker. The chart shows a hopeful, extrapolated curve travelling upwards from around the time of Hypatia that is contrasted with a sudden drop-off followed by a centuries-long scientific “flat-line”. The chart quickly became a visual meme online (one version has the caption: “CHRISTIANITY: Just think, we could have been exploring the galaxy by now”), but it received so much ridicule that Jim Walker felt compelled to issue a response entitled “About that Damned Graph.” (See especially the criticisms of Walker’s chart by atheist historian Tim O’Neill, embedded in his review of James Hannam’s bookGod’s Philosophers.) Undaunted, Walker stuck to the core idea embedded in the chart.

As for Mills, he is either unaware of, or he deliberately neglects, the important role that Christians and Christian institutions played in the innovation and safe-keeping of science during the Middle Ages. (Islam also played both a preservationist and innovatory role in this period; see Syed Nomanul Haq’s chapter in Galileo Goes to Jail.) All of this is airbrushed out of his account: I do not call it history. Nor does Mills shy away from uttering blatant lies about the past:

“… pre-Renaissance man lived during a period when superstition overshadowed rational thought, and when those who proposed scientific explanations were often tortured to death by religious authorities. Galileo narrowly escaped a death sentence imposed by the Catholic Church for his telescopic observation that Jupiter’s moons orbited Jupiter instead of Earth, birthplace of Jesus and presumed orbital hub of the universe.” (p. 85)

It is instructive that Mills does not provide the names of anyone “tortured to death by religious authorities” for proposing “scientific explanations.” There is a simple reason for this. The number of people in Europe put to death by “religious authorities” for science over the many centuries of the entire Medieval and Early Modern periods is precisely zero. A “death sentence” was never imposed on Galileo at any point, and thus it is gratuitous to say that he “narrowly escaped” one. He was never tortured (although he was shown the instruments of torture), but he was placed under house arrest for the last decade of his life (during which time he produced his greatest work of physics, despite having gone blind).

This is not to say that Galileo did not suffer in any way, and it is worth noting that Galileo would sign some of his letters during his house arrest: “from my prison of Arcetri.” Nor is this to deny that Galileo’s enemies in the Church hierarchy were intolerant. As for the question of whether Galileo might have in extremis faced burning at the stake, this is tricky. The Inquisitor’s Manual called for the burning of obstinate heretics, but Galileo recanted and thus it never went that far. If he had not recanted, the legal option was there for the death penalty. Catholic historian James Hannam has argued that this result may eventually have transpired, but only after many years of trying to persuade Galileo to recant. My own view is that this was only a remote possibility, as the Church hierarchy would have worked hard to avoid this outcome. Whatever the case, it did not happen and thus the number of people that Church put to death for “science” remains zero.

As a historian of science, I despair when I read such nonsense, which we frequently encounter amongst some undergraduates entering courses in our programme. It is depressing to see the promotion of such ignorance—and to see it endorsed by Richard Dawkins and the son of Carl Sagan. But one also worries about the effect this vitriol has on secular attitudes towards Christianity and Christians. This sort of rhetoric and misuse of history promotes intolerance and is simply inexcusable. It is the duty of historians to expose this for the mythology it is.

About the author

Stephen Snobelen Headshot

Stephen Snobelen

Dr. Snobelen's research and teaching interests include history of science (early modern and nineteenth century), science and religion, science in popular culture, the popularization of science, radical theology in the early modern period, and millenarianism. His primary research efforts are currently devoted to interpreting Isaac Newton’s theological manuscripts and understanding the relationships between Newton’s science and his religion. Dr. Snobelen has consulted for and appeared in television documentaries on Isaac Newton, including Newton: The Dark Heretic. His most popular course is on science fiction film, which he uses to introduce historical, philosophical, and ethical themes about science and technology to undergraduates in the humanities, sciences, and engineering. He and his wife Julia have four children who help keep them grounded in the more important things of life.