In his unfinished History of Civilisation in England, published in 1857, the self-taught historian Henry Thomas Buckle declared that one of the acute reasons for the unscientific nature of history was that “the most celebrated historians are manifestly inferior to the most successful cultivators of physical science.” “No one having devoted himself to history,” he continued, “who in point of intellect is at all to be compared with Kepler, Newton or many others.” One wonders what Isaac Newton would have made of such a conclusion, given that he devoted the last four decades of his life to writing The Chronology of Ancient Kingdoms Amended, published in 1728, a work of typical Newtonian ambition which attempted to rewrite universal history on a scriptural timeline. Yet, if we can excuse Buckle’s vaulting ignorance on this point, his comments do touch upon an important debate concerning the concept of a “scientific history.” I hope to demonstrate that the historical practice of Isaac Newton, perhaps the greatest figure of the so-called Scientific Revolution of the seventeenth century, and whose work still forms part of the foundations of the modern “hard sciences,” reveals that he would have considered his historical and chronological practice no less “scientific” than his foundational works in mathematics, physics, and natural philosophy. Newton’s cross-disciplinary belief that reliable knowledge should be deduced from “phenomena” gives an important insight into what may be called the “scientific” nature of history.

Newton never explicitly discussed his philosophy of history in the same way that he discussed natural philosophy, the partial progenitor of modern-day science. In a now epochal statement contained in the General Scholium, added to the second edition of Newton’s Mathematical Principles of Natural Philosophy, published in 1713, Newton clearly stated:

“But hitherto I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses. For whatever is not deduced from the phenomena, is to be called an hypothesis; and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction.”

Many historians of science have recognised in this statement Newton’s explicit rejection of René Descartes’ mechanical philosophy as too speculative and hypothetical. Descartes himself admitted in Part III of the Principles of Natural Philosophy, published in 1644, that his vortex theory, which arose from conjectures about the motions of heavenly bodies, relied heavily on hypotheses and was perhaps very far from the truth. Yet Newton did not reject Cartesian methods only in mathematics and physics. He also, as far as we can deduce from his practice, vehemently rejected the Cartesian view of history and historical writing. In his Discourse on Method, originally written in French, Descartes cast doubt not only on the validity but also on the purpose of historical writing, stating that “even the most accurate histories, if they don’t alter or exaggerate things’ importance so as to provide a better ‘read’, are likely to falsify things in a different way: such histories omit most of the meaner and the less striking factors in a situation, so that what they do include appears in a false light, looking grander than it really was.” He went further in criticising historians and those too absorbed in studying the practices of past ages, a sentiment that would be echoed centuries later by C. P. Snow, as those who “usually remain quite ignorant about those of the present century.”

But Newton, whose gravitational theory superseded Descartes’ vortex theory and became the basis for astronomical research for the next 250 years, believed deeply, unlike Descartes, that a “scientific history” could be attained; his historical practice shows that he spent the majority of his later years working toward such an end. One of the key forms of evidence here was the use of mathematics. Descartes’ Principles was almost entirely qualitative and highly speculative, a system of scientific knowledge that Newton explicitly rejected in the Principia, whose core argument was that natural philosophy should be based on strict mathematical principles, as is evident in the title of the publication itself, The Mathematical Principles of Natural Philosophy. Just as Newton believed that the understanding of bodies, motions, and forces should be based on mathematical principles, he also imposed quantification in his attempt to write a universal history and chronology of the ancient world. This stood in sharp contrast to previous chronologers, who based their practices primarily on calendars and eclipses.

For example, in attempting to re-date the chronology of several Greek kingdoms, to establish a new era for the fall of Troy and for the Argonautic Expedition, Newton introduced a quasi-law regarding the duration of reigns, based on his analysis of dynasties for which reliable information existed. As Mordecai Feingold has shown in his article on Newtonian history, Newton argued that kings reigned, on average, around eighteen to twenty years, or slightly longer. Thus, in the early years of the eighteenth century, the twenty-eight kings of England between William the Conqueror and William III reigned for 635 years, averaging 22.6 years per reign. The sixty-three French kings who preceded Louis XIV reigned for 1,224 years, an average of nineteen years per reign.

The rule also applied to antiquity: the ten Achaemenid Persian kings averaged twenty-one years per reign, while the ten Macedonian kings who preceded Alexander the Great averaged 15.5 years per reign. In other words, Newton concluded that, “since Chronology hath been exact, there is scarce an instance to be found of ten Kings Reigning any where in continual Succession above 260 years”; such a conclusion established a rule that conformed to “the ordinary course of nature.”

What is evident in the methodology adopted here is Newton’s attempt to speculate on ancient chronology by building from a body of known and verifiable facts. Variations of this practice are still employed in medieval history, economic history, and modern economics. Indeed, Feingold, a foremost historian of Newton’s historical practice, confirms this by stating clearly that:

“Newton reserved to himself the right to determine not only which historical sources were credible, but which parts of otherwise credible sources were nevertheless untrustworthy and therefore to be discarded. To a considerable extent, then, Newton followed the common practices of contemporary scholars or historians”

Indeed, not just contemporary scholars: the practice highlighted above by Feingold remains central to the work of the modern historian. What is evident from Newton’s entire oeuvre, even in his work as Master of the Mint, is an unparalleled desire to understand the “truths” of the universe, whether that concerned the natural or the historical world. As Newton himself declared, “I shall not stand to recite other men’s opinions, but propose as shortly as I can what I take to be the truth.” This desire to understand the “truth” of the past is the scientific nature of history as Newton himself would have understood it. Whatever fallible attempts are made in the course of this endeavour are not fundamentally different from the factual errors that have decorated the annals of the hard sciences.

As Arthur Marwick succinctly described in his rebuttal to Hayden White, the vanguard of postmodern excess:

“Just as the natural sciences are systematic studies, through experimentation, observation, and related methods, of the natural world, and just as the bodies of knowledge arising from those studies constitute physics, biology, chemistry, and other sciences as known through the work of scientists, so history is the study of the human past through the systematic analysis of primary sources, and the bodies of knowledge arising from that study. History, therefore, is the human past as it is known from the work of historians”

Historians, as Eric Hobsbawm has also said, “are professionally obliged not to get it wrong — or at least to make an effort not to.”

Much of this aligns with Newton’s historical work, to which he devoted a considerable portion of his life, labouring tentatively, as he did in his natural-philosophical works, not to “get it wrong.” This does not mean that Newton’s chronology was error-free because of its methodology. Indeed, like his natural philosophy, Newton’s chronology drew fierce attention and criticism for nearly a century after its publication, just as the Principia drew criticism from Leibniz and other natural philosophers for its method of generalising about gravity from phenomena whose causes remained unobserved. The argument here is not simply that historians are scientists and should prance around in lab coats. Newton himself was not a scientist in the modern sense. Rather, it is that historians and scientists work in similar epistemological worlds, where demonstrable, criticisable, and falsifiable knowledge remains paramount. This epistemological world is the scientific nature of history.