Eye on the Present—The Whig History of Science

It was the Cambridge historian Herbert Butterfield who described and condemned what he called “the Whig interpretation of history.” In a book with that title, the young Butterfield in 1931 declared that “the study of the past with one eye, so to speak, upon the present is the source of all sins and sophistries in history….”¹ He spread special scorn on those historians, including Lord Acton, who subject the past to contemporary moral judgments, who for instance are unable to see the Whig Charles James Fox as anything but a savior of British liberties. Not that Butterfield was personally unwilling to make moral judgments; he just did not think it was the business of historians. According to Butterfield, the whig historian studying Catholics and Protestants in the sixteenth century feels that some “loose threads are still left hanging unless he can show which party was in the right.”

Butterfield’s strictures were fervently taken up by later generations of historians. Being called “whig” came to seem as terrifying to historians as being called sexist, or Eurocentric, or Orientalist. Nor was the history of science spared. The historian of science Bruce Hunt recalls that when he was in graduate school in the early 1980s, “whiggish” was a common term of abuse in the history of science. To avoid that charge, people turned away from telling stories of scientific progress or from giving “big picture” stories of any kind, and shifted to accounts of small episodes, tightly focused in time and space.

Nevertheless, in teaching courses on the history of physics and astronomy, and then working up my lectures into a book, I have come to think that whatever one thinks of whiggery in other sorts of history, it has a rightful place in the history of science. It is clearly not possible to speak of right and wrong in the history of art or fashion, nor I think is it possible in the history of religion, and one can argue about whether it is possible in political history, but in scientific history we really can say who was right. According to Butterfield,

we can never say that the ultimate issue, the succeeding course of events, or the lapse of time have proved that Luther was right against the Pope or that Pitt was wrong against Charles James Fox.

But we can say with complete confidence that the lapse of time has shown that, about the solar system, Copernicus was right against the adherents of Ptolemy, and Newton was right against the followers of Descartes.

Though the history of science thus has special features that make a whig interpretation useful, it has another aspect that makes the idea of keeping an eye on the present troublesome to some professional historians. Historians who have not themselves worked as scientists may feel that they cannot match the working scientist’s understanding of present science. On the other hand, it must be admitted that a scientist like myself cannot match the professional historian’s mastery of source material. So who should write the history of science: historians or scientists? The answer seems to me obvious: both.

I should disclose that I have a dog, or at least a book, in this fight. In To Explain the World: The Discovery of Modern Science, based on my lectures at the University of Texas at Austin, I acknowledged that “I will be coming close to the dangerous ground that is most carefully avoided by contemporary historians, of judging the past by the standards of the present.” Reviews were generally favorable, but one in The Wall Street Journal (by a professional historian) took me to task for my attention to the present. The review was headed “The Whig Interpretation of Science.”

Now, some criticisms of whiggery, by Butterfield and others, are either irrelevant to the history of science or not controversial. Certainly we should not oversimplify or pass moral judgments, designating some past scientists as spotless heroes or infallible geniuses, and others as villains or fools. For instance, we must not gloss over Galileo’s getting it all wrong in a debate over comets with the Jesuit Orazio Grassi, or Newton’s fudging his calculations to achieve agreement with observations of the precession of the earth’s axis. In any case, it is ideas and practices that we should hold up to present standards, not individuals. Above all, we must not imagine that our predecessors thought the way we think, only with less information.

It is Butterfield’s injunction against presentism, “the study of the past with one eye, so to speak, upon the present,” that still represents a serious challenge to whiggish historians of science. In laying out maxims for a history of science that emphasizes its internal development, Thomas Kuhn in 1968 argued that “insofar as possible (it is never entirely so, nor could history be written if it were), the historian should set aside the science that he knows.”² A more uncompromising stand against using present knowledge was taken by several sociologists who study science as a social phenomenon, including the well-known Sociology of Scientific Knowledge group at the University of Bath.

Meanwhile, whiggery in the history of science has not lacked defenders. They are found especially among those, like Edward Harrison, Nicholas Jardine, and Ernst Mayr, who have worked as scientists.³ I think that this is because scientific history with an eye to present knowledge is needed by scientists. We don’t see our work as merely an expression of the culture of our time and place, like parliamentary democracy or Morris dancing. We see it as the latest stage in a process, extending back over millennia, of explaining the world. We derive perspective and motivation from the story of how we reached our present understanding, imperfect as that understanding remains.

Certainly history should not ignore those influential past figures who turned out to be wrong. Otherwise we would never be able to understand what it took to get things right. But the story makes no sense unless we recognize that some were wrong and some right, and this can be done only from the perspective of our present knowledge.

Right and wrong about what? A whig history of science that amounts just to a totting up of plus and minus scores for whatever facts a past scientist has gotten right or wrong would not be very interesting. Much more important, it seems to me, is to trace out the slow and difficult progress that has been made over the centuries in learning how to learn about the world: What sort of questions can we hope to answer? What sort of notions help us to these answers? How can we tell when an answer is correct? We can identify which historical practices set future scientists on the right path, and which old questions and methodologies had to be unlearned. This can’t be done without taking account of our present understandings, so painfully acquired.

For an example of a whiggish judgment of the past, take the ancient fundamental question: Of what substance is the world made? Much credit is often given to Democritus of Abdera, who around 400 BC proposed that matter consists of atoms moving in the void. One of the leading universities in Greece today is named after Democritus. Yet from a modern perspective, the good guess of Democritus about atoms represented no progress in the methods of science. None of the many surviving fragments of Democritus’s writings describe any observation that could suggest the existence of atoms, and there was nothing that he or anyone else in the ancient world could do with this idea that would confirm that matter really does consist of atoms. Though right about matter, Democritus was wrong about how to learn about the world. In this he was not alone; no one before Aristotle seems to have understood that speculative theories about matter need to be confirmed by observation.

One’s judgment of Aristotle provides a good test for one’s attitude toward the history of science, for Aristotle was in a limited sense the first scientist, and much of the subsequent history of science consisted of responses to his teaching. Aristotle argued that the earth is a sphere, not only on the theoretical grounds that this shape allows the greatest amount of the element earth to get closest to the center of the cosmos, but also on the basis of observations: the shadow of the earth on the moon during a lunar eclipse is curved, and the starry night sky changes its appearance as one travels north or south.

However, Aristotle’s work shows no understanding that mathematics should be an important part of the study of nature. For instance, he made no attempt to use observations of the night sky at different latitudes to estimate the circumference of the earth. His theory that the planets ride on spheres pivoted on other spheres, all with the earth at their center, agreed only qualitatively with their observed apparent motions; but the failure to get quantitative agreement with observation did not bother him or many of his followers.

Mathematics began to be used constructively in scientific theories in the Hellenistic Age and then in the Greek part of the Roman Empire. Around 150 AD Claudius Ptolemy put the final touches on a mathematical theory of the solar system that agreed pretty well with observation. (In the simplest version of Ptolemy’s theory, planets travel along circles called epicycles, whose centers travel around larger circles that have the earth at their center.) With the benefit of present knowledge this agreement is not surprising, because in its simplest version Ptolemy’s theory gives precisely the same predictions for the apparent motions of the sun, moon, and planets as the simplest version of the later theory of Copernicus. Yet for a millenium and a half there continued a debate between followers of Ptolemy, called astronomers or mathematicians, and adherents of Aristotle, often called physicists. Ptolemy was wrong about actual motions in the solar system, but right about the need for quantitative agreement with observation.

It was one of the great achievements of the scientific revolution of the sixteenth and seventeenth centuries to work out the modern relation of mathematics and science. Mathematics had been important to the Pythagoreans as a form of number mysticism, and to Plato as a model for a purely deductive science that experience has shown could never work. The modern relation between mathematics and natural science was spelled out by Christiaan Huygens, in the 1690 preface to his Treatise on Light:

There will be seen in [this book] demonstrations of those kinds which do not produce as great a certitude as those of Geometry, and which even differ much therefrom, since whereas the Geometers prove their Propositions by fixed and incontestable Principles, here the Principles are verified by the conclusions to be drawn from them; the nature of these things not allowing of this being done otherwise.

The remarkable thing is not that Huygens understood this, but that, well into the seventeenth century, it still needed to be said.

Aristotle saw no need for experiment in the sense of the artificial arrangement of circumstances that are more revealing than what we encounter naturally. This presumably was because he thought there was a profound difference between the natural and the artificial, with only the natural world worth study. Like Plato, he thought that it is only possible to understand things when one knows their purpose. These ideas stood in the way of learning how to learn about the world.

Such judgments on Aristotle and on his followers are just the sort of thing that is still often condemned by some historians—keeping one eye on the present in studying the past. For instance, a distinguished historian of science, the late David Lindberg, commented that

it would be unfair and pointless to judge Aristotle’s success by the degree to which he anticipated modern science (as though his goal was to answer our questions, rather than his own).⁴

And in a second edition of the same work: “The proper measure of a philosophical system or a scientific theory is not the degree to which it anticipated modern thought, but its degree of success in treating the philosophical and scientific problems of its own day.”

To me this is nonsense. The point of science is not to answer the questions that happen to be popular in one’s time, but to understand the world. Not that we know in advance what kinds of understanding are possible and satisfying. Learning this is part of the work of science. Some questions like “What is the world made of?” are good questions, but are asked prematurely. No one could make progress in answering this question until the advent of accurate measurements of chemical weights at the end of the eighteenth century. In the same way, the effort at the start of the twentieth century of Hendrik Lorentz and other theoretical physicists to understand the structure of the recently discovered electron was premature: no one could make progress on the electron’s structure until the advent of quantum mechanics in the 1920s. Other questions like “What is the natural place of fire?” or “What is the purpose of the moon?” are bad in themselves, leading away from real understanding. Much of the history of science has been a matter of learning what sort of questions should and should not be asked.

I am not arguing that whig history is the only interesting sort of history of science. Even a whig historian may be interested in exploring the impact of general culture on developments in science, or vice versa, without needing to worry about the role that these developments played in progress toward modern science. For instance, the atomic theory of Democritus offered an illustration of how the world might work without the intervention of the gods, and thereby had a great influence a century later on the Hellenistic philosopher Epicurus and later still on the Roman poet Lucretius, an influence that did not depend on whether the theory was well grounded by modern standards, which it wasn’t. Likewise, you can feel the impact of the scientific revolution on general culture in such works as the poetry of Andrew Marvell (I think particularly of his poem “The Definition of Love”). The influence also runs in the opposite direction. The sociologist Robert Merton argued that Protestantism had a major part in fostering the great scientific advances of seventeenth-century England. I don’t know if that is true, but it’s certainly worthy of interest.

But there is an element of whiggery even here. Why should a historian of science focus on the intellectual environment of, say, Hellenistic Greece or seventeenth-century England, if it were not that something was happening then that advanced science toward the present? The history of science is not merely a tale of intellectual fashions, succeeding one another without direction, but a history of progress toward truth. Though this progress was denied by Thomas Kuhn, it is felt strongly by working scientists. Thus whig history is not just one of several interesting kinds of scientific history. The evolution over many centuries of modern science is a great story, as important and interesting as anything else in the history of human civilization.

Butterfield himself seems to have had a sense of the legitimacy of whiggery in the history of science. In his 1948 lectures at Cambridge on the history of science, he attributed a historical importance to the scientific revolution that he would never grant to England’s Glorious Revolution, so beloved of the Whigs.⁵ I found his account of the scientific revolution thoroughly whiggish, and that impression was shared by others, including A. Rupert Hall, a student of Butterfield’s.⁶

Much earlier, in The Whig Interpretation of History, Butterfield had already shown himself potentially receptive to a whig interpretation of history under some conditions. He acknowledged that if morality were “an absolute system, equally binding on all places and times,” then the historian would “be driven now to watch the story of men’s growing consciousness of the moral order, or their gradual discovery of it.” Though a devout Methodist, Butterfield did not believe that there is an absolute moral order that is revealed to us by history or religion or anything else.⁷ But he did not doubt that there are laws of nature, equally binding on all places and times. It is precisely the story of the growing consciousness of the laws of nature that the whig historian of physics hopes to tell, but the story cannot be told without keeping an eye on our present knowledge of the natural world.