The Popular History of Science
The popular history of science is usually pretty awful. Sometimes the awfulness stems from an ideological bias, typically against religion. But many other times, people simply have no idea what they are talking about, and think they can just make up history based upon "this is how it must have happened!" This chapter examines some popular myths about the history of science.
Recently, after looking in an introductory biology textbook for a description of meiosis, I browsed through its introduction. There, I came upon the following passage:
For 2,000 years prior to [the Renaissance], scholars had accepted the writings of Aristotle and other ancient philosophers, as well as certain Church doctrines, to be unfaltering truths about the natural world. It took some of the greatest minds in history, including Copernicus, Galileo, and Newton, to shake this dominion of dogma and to replace it with theories and laws based on direct observation of nature. Nicholaus Copernicus, and later Galileo, made calculations that the Earth and other planets circle the sun... (Wessells and Hopson, 1988, p. 11).
Many science textbooks contain similar one-or-two-paragraph histories of how modern science miraculously emerged from the dark swamp of ignorance we call the Middle Ages. The main problem with such stories is that they are almost entirely false. Let's compare the picture painted above with the current understanding of scholars studying the history of the Scientific Revolution.
The first assertion, quite a commonplace one, is that from the time of the ancient Greeks until the Renaissance, the European mind was in the thrall of a dogmatic worldview, based only on authority, and made no progress toward a better understanding of the natural world. It is certainly true that scientific ideas developed much less rapidly during most of the period in question than they have in recent centuries. (Even admitting that much, the figure of "2000 years" in the quote above still seems to overshoot the mark, since it includes the time of pioneers like Archimedes and Ptolemy within its scope.) During the "Dark Ages," in the centuries immediately after the fall of Rome, Western Europe did not challenge the received wisdom in science primarily because it did not do much science at all. People were struggling to survive, and intellectual life fell into abeyance. In fact, contrary to the view expressed in the biology textbook, for most of that period, Aristotle's writings were lost to the West, so that they could hardly have been accepted as "unfaltering truths"!
But as Western European intellectual life revived, scholars began reconsidering the ideas of the ancients. As Bede's Library has it:
When Aristotle was rediscovered in the West, it was soon established that when there were clear conflicts between his philosophy and the Christian faith, the latter should always prevail. This was not much of a handicap, as on the subject of physical science, faith did not really have a lot to say. The bible could be read non-literally where necessary, as Augustine himself allowed, so William of Conches could even call the creation account in Genesis figurative. Nearly everyone agreed that the earth was a sphere even though the Bible implied a flat earth. But where Aristotle and faith were in clear conflict, such as his claim that the world was uncreated and eternal, it weakened his authority and allowed his ideas to be challenged. This opened the door to the idea of a developing body of knowledge, which is often assumed to have been absent from the medieval outlook."
For example, in the fourteenth century, a group of philosophers, most of them at the University of Paris, developed the impetus theory of motion. It was both a break with one of the central ideas of Aristotle's physics, and a step toward the modern theory of inertia. They also disputed the prevailing belief that the movement of each planet was guided by a conscious being:
"Although the theory of celestial intelligences became a central doctrine in Hellenic, Arabic and scholastic cosmology, it was attacked during the fourteenth century by several scholars, and most incisively in the work of Jean Buridan (died c. 1358) and his pupil Nicole Oresme (1320-1382)."
Nevertheless, Aristotelian physics did remain the primary means of explaining most physical phenomena well into the Scientific Revolution. There is a very good reason for that, which brings us to our next point. The textbook cited above claims that scientists such as Copernicus, Galileo, and Newton were able "to shake this dominion of [Aristotelian] dogma" with "theories and laws based on direct observation of nature." Once again, the authors are repeating a commonplace view, one that appears in a multitude of popular accounts of the rise of science. The scholastic philosophers who dominated the medieval universities, enraptured with their elaborate metaphysical speculations, ignored the plain facts of the physical world, which were accessible to them if they had simply looked around. The great figures of the Scientific Revolution relied instead on observation, which led them to develop the theories that replaced Aristotelian physics.
But this story, inspiring though it is, runs afoul of the fact that Aristotle was a masterful observer, one whose physical theories are closely based on the world as it appears to the unaided senses. Knowledge, he held, begins with our observations of the world around us. Similarly, Ptolemy constructed his Earth-centered model of the cosmos to accurately reflect the best astronomical observations available to him.
In fact, it was the pioneers of the Scientific Revolution who had to overcome the commonsense view of the world revealed by direct observation in order for their theories to gain acceptance. The most obvious discrepancy between the reports of our senses and the new ideas is that the Earth seems quite plainly to be standing still, while the heavenly bodies clearly appear to be rotating around it. Renaissance man had no experience of, for instance, traveling in an airplane at 600 miles per hour yet feeling as though he wasn't moving. When he moved rapidly, such as on horseback, he could feel that he was moving. And to account for the apparent motions of the heavenly bodies, the Earth would have to rotate at what, for him, was a truly astonishing rate. (At the equator, the actual speed is over 1000 miles per hour.)
What's more, if the Earth was spinning around that rapidly, it seemed that we ought to be able to detect that motion in many ways. For example, if you dropped a rock from a tower, it should fall some distance from the tower's base, in the direction opposite to the Earth's rotation, since the ground would have moved under it as it was falling. The Earth's atmosphere would also be left behind, so that there would be a continuous wind sweeping from east to west at hundreds of miles per hour.
On a more technical level, a major reason that Copernicus's heliocentric (sun-centered) theory was rejected by many leading astronomers of the sixteenth century was the absence of any observed parallax in the "fixed stars." Parallax is the astronomical term for the fact that objects will appear to change their location when observed from different places. If the Earth revolves around the sun, the stars should appear to move slightly during the course of the year, but astronomers observed no such phenomena. (The explanation for that failure is that the stars are much farther away from the Earth than anyone at that time suspected, so that the parallax was too minute for their instruments to detect.)
Copernicus handled the difficulty that presented for his theory with an ad hoc hypothesis, declaring that the sphere of the stars was ten times farther from the Earth than had previously been believed. Not only was the hypothesis ad hoc, it was also, as a Popperian would put it, unfalsifiable: there were no instruments available at the time to measure a parallax as small as the new distance implied. And if a geocentric astronomer had developed a device capable of measuring such a slight change in observed position, Copernicus could (and undoubtedly would) have simply moved the stellar sphere ten times farther away still.
Copernicus also "was puzzled by the variations he had observed in the brightness of the planet Mars. [But] Copernicus's own system was so far from answering to the phenomena in the case of Mars that Galileo in his main work on this subject praises him for clinging to his new theory though it contradicted observation..." (Butterfield, 1949, p. 23).
What's more, as we noted above, Copernicanism violated many of the principles of the Aristotelian physics of his time. Copernicus could not explain why objects didn't fly off the rotating Earth, why the Earth didn't spin itself apart, why dropped objects fell straight to the ground, or what kept celestial objects going in their orbits if not the motion transmitted from sphere to sphere in the Ptolemaic/Aristotelian model. Aristotelian physics explained all of those phenomena in ways that made sense of the observational experience then available. As Butterfield writes:
In fact, you had to throw over the very frameboard of existing science, and it was here that Copernicus clearly failed to provide an alternative. He provided a neater geometry of the heavens, but it was one which made nonsense of the reasons and explanations that had previously been given to account for the movements in the sky (1949, p. 27).
Of course, Aristotelian physics had difficulties of its own, but Copernicanism introduced a whole host of new problems, while only eliminating a few: "Most of the essential elements by which we know the Copernican Revolution — easy and accurate computations of planetary position, the abolition of epicycles and eccentrics, the dissolution of the spheres, the sun a star, the infinite expansion of the universe — these and many others are not to be found anywhere in Copernicus's work" (Kuhn, 1957, p. 135).
Nor does the frequent assertion that Copernicus's theory was significantly simpler than Ptolemy's stand up to scrutiny. As Lakatos notes:
The superior simplicity of the Copernican theory was just as much of a myth as its superior accuracy. The myth of superior simplicity was dispelled by the careful and professional work of modern historians. They reminded us that while Copernican theory solves certain problems in a simpler way than does the Ptolemaic one, the price of the simplification is unexpected complications in the solution of other problems. The Copernican system is certainly simpler since it dispenses with equants and some eccentrics; but each equant and eccentric removed has to be replaced by new epicycles and epicyclets.... he also has to put the centre of the universe not at the Sun, as he originally intended, but at an empty point fairly near to it.
The suggestion that Galileo had all of the evidence on his side in his battle against the Aristotelians and the Church is also erroneous. In his book Two Systems one of the major pieces of evidence he advanced for the Copernican model was the existence of tides. Galileo explained them as arising from the motion of the Earth rocking the oceans back and forth, much as a swinging a bucket containing water will slosh the water up one side of the bucket and then the other.
Of course, this is quite different from our current understanding of tides as arising from the gravitational influence of the moon. But what is really surprising about Galileo's hypothesis, given his common portrayal as a staunch empiricist, is that he had not even investigated the actual period of the tides before forwarding this argument! His theory required a 24-hour tidal cycle, while in fact it is 12 hours. When he learned that sailors in the Mediterranean reported high and low tides occurring every 12 hours, he explained this glaring discrepancy as resulting from local variations in the ocean bottom. (See Shea and Artigas, 2003.)
Galileo also failed to be a "good empiricist" when he ignored his ally Kepler's theory that the planets orbit the sun in elliptical, rather than circular, paths. Kepler's model fit the data much better than Galileo's, yet Kepler's letters to Galileo suggesting elliptical orbits never even solicited a response.
When one looks at the real history of the Scientific Revolution, it becomes apparent that observation was rarely the prime impetus for the development of the most important new theories. Instead, leading scientists drew their main inspiration from their beliefs about the kind of world they envisioned that God would create. Copernicus and Kepler were Neo-Platonists, and it seemed to them that the Sun, the most brilliant light in our world, was a more fitting center for God's creation than the Earth. Copernicus was also dissatisfied with the Ptolemaic model of the heavens because it centered the orbits of heavenly bodies not on the Earth, the supposed center of the cosmos, but on a point called the equant, which was an empty spot in space near to the Earth. Newton was a deeply religious man, who believed that God's work would naturally exhibit the sort of mathematical perfection he hoped to reflect in his own theories.
I came across another very common idea about the Scientific Revolution in browsing a recent issue of National Geographic. Speculating on the impact of the possible future discovery of other, earth-like planets, the article's author writes:
It's hard to overstate the excitement scientists feel at the prospect of seeing that faint blue dot. If it told of a watery, temperate place, humanity would face a 21st-century version of Copernicus's realization nearly 500 years ago that the Earth is not the center of the solar system. The discovery would show ‘that were not in a special place, that we might be part of a continuum of life in the cosmos, and that life might be very common,' says Michael Meyer, an astronomer at the University of Arizona.
As a corollary of the above, it's often suggested that many people in the sixteenth and seventeenth centuries rejected the idea of a sun-centered solar system because it displaced the Earth from its unique location at the center of the universe, and therefore seemed to make humanity less important in the scheme of creation. However, Professor John Milton, with whom I studied the history of science at King's College in London, noted that historians have discovered no evidence of any of the contemporaries of Copernicus or Galileo voicing such a concern. And that is not too surprising, when we consider that, in the prevailing cosmology of the time, the center of the cosmos was not a very prestigious place to be. Aristotle regarded it as the region to which gross and corrupt matter gravitated, distinctly inferior to the unchanging perfection exhibited by the heavens. And in Dante's Divine Comedy, the occupant of the Earth's center, and therefore at the precise center of the universe, was none other than Satan himself. To place the Earth in the heavens was to grant it a promotion.
None of what I have presented above is meant to claim that the conservatism typical of entrenched interests, for instance, of the Aristotelians who dominated the universities of the 16th and 17th centuries, did not present an extra-scientific hurdle that new conceptions of the physical world had to surmount, or that the Catholic Church never resisted the progress of science for dogmatic reasons.
But the common, popular version of the history of science, in which unselfish, heroic scientists do battle with the backward forces of religion, is a fairy tale, spun mostly by Voltaire and his followers, in order to discredit the religious belief that they despised. The real history of the Scientific Revolution is much more complex and nuanced than the simplistic morality play they made it out to be. If we are truly interested in understanding the roles that religion and science have played in creating our civilization, we should put aside the myth and attend to the reality.
The blogger "Renaissance Mathematicus" gives an example here. The author of the piece critiqued -- which was published by Scientific American! -- puts forward nonsense like "Copernicus's system did not explain retrograde motion of the planets" -- when, in fact, the major advance of Copernicus's system was its natural explanation of retrograde motion! -- and that Galileo "discovered that Venus was a planet and not a star" -- something the ancient Greeks knew quite well. I studied the history of science for a year at King's College in London. Pretty much the first thing our lecturer told us was that pop history of science was complete nonsense. And note: although sometimes the junk pop history of science involves religious issues, nothing in the Scientific American piece has anything to do with such matters. It just seems that, concerning the history of science, lots of people who have no idea what they are talking about want to publish on the topic.
I just picked up The Scientists by John Gribbin. I had thought I was bying a book on the history of science, but unfortunately I've discovered I have bought a work of ideology disguised as history.
Gribbin opens by saying "The most important thing science has taught us about our place in the Universe is that we are not special." Oh really, and just how did science discover that "fact"? Is there some "specialness-omter" scientist have invented recently? What is the measure of "specialness" that proves Gribbin's assertion?
There is none, for of course the assertion is sheer rubbish. The contention of Christianity, Buddhism, Judaism, and so on is not that humanity is special in possessing some unique physical property -- which science might be able to disprove -- but that humanity is spiritually special. Buddhism, for instance, contends that humans are spiritually uniquely positioned to achieve enlightenment. Just how is science supposed to have "taught" us that this is not so?
One of Gribbin's arguments for how science shows we are not special is the old chestnut about the Copernican system removing man from his "special" location at the center of the universe, a move that supposedly "demoted" man from a place of prime importance in creation. There is one rather serious problem with this oft-repeated tale: while it is true that, in Aristotelean and Medieval cosmologies, the center was a special place to be, that is because it was an especially bad place. For Aristotle, the center was where gross, corrupt matter descended, and it was the heavens that were perfect and unchanging, and the closest realm to God. As my lecturer in the history of science at King's College, John Milton, asked: Who was at the center of the universe in Dante's Divine Comedy? Why, Satan, of course, and hell! And Professor Milton mentioned that he could find no record of anyone at the time worried about Copernicus because man would no longer be at the center. This idea is almost certainly an invention of the same Enlightenment anti-clerical thinkers who invented "The Middle Ages," and who falsely alleged that Medieval natural philosophers held that the Earth is flat.
Gribbin continues: "It would have been natural [given the great ruins left by the Ancients] to accept that they were intellectually far superior to the ordinary people who had followed them, and to accept the teaching of the ancient philosophers such as Aristotle and Euclid as a kind of Holy Writ, which could not be questioned."
But that is precisely what Medieval thinkers did not do with Aristotle. Medieval thinkers generally considered themselves the superiors, not the inferiors, of the Ancients, because they had Christ's revelation at hand. Indeed, many Christian thinkers urged their fellows to ignore the Ancient philosophers as having nothing to teach Christians. And almost as soon as Aristotle's works were re-discovered, they were questioned. The Church issued edicts as to the many contentions of Aristotle's that had to be rejected. Buridan and Orseme seriously modified his mechanics. The idea that these people unthinkingly accepted Aristotle's every word is historical nonsense.
Euclid is a somewhat different story, for, while Euclid was unchallenged in the Middle Ages, so he was also unchallenged by Copernicus, Kepler, Galileo, Newton, and Kant! It was not until the 19th-century that non-Euclidean geometries were developed.
And, ironically, the attitude of inferiority to the Ancients really came to the fore with the rise of Humanism in the Renaissance -- just when Gribbin says it was ending!
Gribbin actually gets much, much better once he is done with the Middle Ages. I have the feeling he actually researched the period from 1450 on, whereas he just cribbed popular opinion for his views on everything earlier.
The great figures of the Scientific Revolution -- Galileo, Kepler, Newton -- were crystal clear on why science could be a rational enterprise: scientists were reading Nature, "the book of God"... and God being the supremely rational mind, naturally the book had a rational design, one that, with effort, our more limited minds could follow.
The major part of the history of the philosophy of science since the 18th-century has been the hunt to find some other, any other, basis for science's rationality. Once Hume destroyed the purely empiricist case for science, the search had an air of desperation to it. Instrumentalism, verificationism, falsificationism: all were attempts to patch up the hole Hume had noted.
All these attempts have failed.
An actual historian looks at a pop "history" of science column and discovers it is about as accurate as an explanation of evolution that says, "And one day a fish grew legs and walked up onto the land." And Christie even missed a problem with the pop history account, in which Potter wrote "...how the young Newton, sent home from school at Cambridge to avoid the plague of 1665, was sitting under a tree one day, saw an apple fall to the ground, and, in a flash of insight, came to understand the workings of gravity." Christie notes that "the flash of insight" part is absurd, and it took Newton another twenty years to put his thoughts in publishable form. But the problem Christie misses is the idea that Newton ever "came to understand the workings of gravity": he did not. He devised a formula describing how objects under the influence of gravity would behave. But he had no model or theory of how gravity was producing this behavior, a fact which he readily admitted himself.
Some of you may be inclined to suspect that I am rough on pop history because pop history is sometimes rough on religion. This, despite the fact that I keep noting that serious historians who are atheists are pretty rough on the pop history of the church versus science as well.
But the latest episode of Cosmos dealt with an episode in history where religion does not really enter in at all. And it just completely bungs it up.
For me, the most stunning howler was that Neil deGrasse Tyson says that the Principia was where Newton introduced calculus. Of course, it has no doubt been the topic of many a PhD thesis to ask "Given Newton had already invented calculus, why didn't he use it at all in the Principia?"
In other words, the complete absence of calculus from the Principia is a famous problem in the history of science. But the scriptwriters for a show supposedly about the history of science completely overlooked this, and claimed instead that the Principia was where calculus had been introduced!
It is often imagined, by partisans of both science and religion, that those two domains are in rivalry for providing the "best" explanations of the nature of the world in which we find ourselves. If there is a valid scientific explanation for, say, the origin of life on Earth, then any religious understanding of the topic is rendered superfluous. The consequence is that many people who appreciate the accomplishments of science conceive religion to be merely an impediment to scientific progress, while numerous religious folk feel compelled to reject the possibility of scientific explanations in some realm that they see as intimately tied to their beliefs.
The idea behind this supposed conflict is that "God" serves as a kind of default causal mechanism invoked to explain anything not yet understood scientifically. Thus, if current science has no explanation for the existence of living creatures, then that is seen -- superstitiously, according to one camp, or faithfully, according to the other -- as evidence that there is still "room" for God in our world view. And, if scientific advances should conquer that problem, then it is hoped or feared that the territory plausibly claimed by religion will be reduced by just the area now newly occupied by science.
I suggest that both sides in this battle are profoundly mistaken about the relation of religious and scientific "explanations," in that those two modes of human understanding are categorically differentiated from each other, to the extant that "explanation" does not even mean the same thing in one mode as it does in the other.
I will attempt to clarify my contention through illustration. Consider the (highly improbable) case of a society lacking even the most rudimentary scientific explanations of anything whatsoever. Everything that happens is seen as merely a brute fact, accepted as just an instance of "the way things are." That complete absence of scientific thinking leaves entirely undetermined the religious attitude of that society: the members might view these simply given conditions as representing an entirely arbitrary state of affairs that just happens to be what faces them, or as resulting from the design/will/intention/self-expression of some divine power at their source.
Now, let's imagine these people hit upon the notion of natural regularities that govern the course of what previously seemed to be totally contingent, particular goings-on in the world. Perhaps they recognize that not only did that apple and that rock and that stick fall to the earth when dropped, but that that there is a general tendency for any heavy object to do so. Of what relevance is the emergence of this first glimmering of scientific awareness to making a choice between the two fundamental religious attitudes described above? None at all, I contend: It is true that the choice has been shifted to a different level, but its essence is unaltered. Now, the question is whether the general law that heavy things will fall towards the earth when unencumbered just happens to be the way things are, or does it arise in accordance with some greater order perceived as "sacred" in nature.
If you have grasped the irrelevance of scientific progress to the central religious issue in this primitive case, it should be obvious that, however far science travels beyond that first baby step, its findings cannot possibly substitute for religious understanding or adjudicate between the primary and opposed answers to the question of God.
Nothing in the above musings is intended to convince a sceptic that his negative conclusion on the "God issue" is mistaken. Rather, I have tried to show that the issue cannot be resolved by scientific progress, since both positions regarding it are compatible with any and all scientific findings. I hope I have opened the minds of at least a few of the many atheists whom I respect and admire to the possibility that religious faith does not represent an attempt to ignore the findings of science or a rejection of rational inquiry, but is, instead, a different conception of the essential character of the stage upon which science and reason play their parts, a conception that cannot be dismissed by quoting the lines that those actors speak.
A side note: In discussing what constitutes an explanation, as mentioned above, one of the most esteemed achievements in the entire history of science, Newton's theory of gravity, did not actually provide any explanation of gravity at all, at least not in a scientific sense. In lieu of offering an answer as to why an apple fell to the earth, he presented a quantitative law giving the rate at which it did so, a substitution for which he was roundly criticized by the followers of Descartes, who accused him of regressing to the "occult" and unscientific form of natural philosophy prevalent in the Middle Ages. However, Newton did have a personal preference for explaining why gravity operated as it did: he suggested that Spirit pervades the realm of matter, and imbues all material objects with mutual attraction. Ouch!
A reader sent me an interesting note on whether or not evolution is "a fact" (see the chapter on "Darwin and Evolution" in this work), interesting because it clearly expresses the "received view" of science, the one we all were taught in whatever formal science courses we took in school.
He contested the idea that all scientific facts are open to revision with an example: "By fact I mean: when I hold this pencil over the desk and let go, it falls to the desk."
But did it? Or did the desk, and the rest of the Earth, rise up to meet the pencil? Before I go any further with this point, let me introduce another quote: "I don't think there were all that many facts supporting geocentrism."
Now, my correspondent might want to claim that it is the plain and indisputable evidence of our senses that tells us that the pencil falls towards the Earth, rather than the Earth moving towards the pencil. But, if he consistently relies on this sort of argument, he will wind up as an Aristotelean physicist, defending geocentrism! After all, one of the most convincing arguments for geocentrism was that it is plainly evident to our senses that the Sun is moving and the Earth is stationary. Galileo, in making his case for heliocentrism, devoted a great deal of effort to demonstrating that our senses could mislead us about such matters.
And, in fact, per Newton's theory of gravity, the Earth does move up towards the pencil, if only a minuscule distance -- Newton's theory is one of mutual attraction, so that the pencil is attracting the Earth even as the Earth is attracting the pencil. Although I don't know that this specific argument was actually made, an Aristotelean might very well have rejected Newton's theory based on our clear perception that the pencil is moving and the Earth is not.
He goes on to say: "If there are no 'indisputable' facts as you say, then I'm out of my league, but you must be talking about philosophy. I'm talking about hard science, where we must have some facts."
This is a common way to attempt to maintain the Enlightenment view of science in the face of recent developments in the philosophy and the history of science -- dismiss philosophy as an ivory tower enterprise with which "hard science" need not be concerned. Now, it is true that the practicing scientist does not necessarily need to be familiar with the ideas of the philosopher of science to do his job. Nor is it the philosopher's business to dictate correct practice to the scientist. However, as soon as one begins to talk about the meaning of scientific results, their truth value, and so on, one is, willy-nilly, engaged in philosophy. Indeed, the question of what makes some activities "hard science" and others not is a philosophical, not a scientific, one. (We can't answer it scientifically because trying to do so assumes we already know what makes an answer scientific -- but that is the very question on the table!) The dismissal of philosophy of science as irrelevant noodling about only results in the adoption of a philosophy of science that has not been critically examined.
As I noted at the top of this section, my correspondent's view is representative of the notion of science commonly forwarded in science education. Science, properly regarded, is a coherent, worthwhile, and, at least to me, fascinating enterprise. But when it is portrayed as the sole route to truth and knowledge, it is placed in a role it cannot live up to, to the detriment of other ways of comprehending human experience.