The Forgotten Revolution. How Science Was Born in 300 BC and Why it Had to Be Reborn by Lucio Russo

Lucio Russo
The Forgotten Revolution
How Science Was Born in 300 BC and Why it Had to Be Reborn
Springer 2004

The forgotten revolution is not a harmless book. Despite being ultimately an ancient history book, it possesses the remarkable ability of taking a hammer to your certainties and hitting them repeatedly until they crumble to dust. Certainties about ancient history, you ask? Sure, but certainties about mathematics and the scientific method as well.

For one thing, there are two cultures, meaning the so-called humanities and the techno-scientific continuum or STEMM, with a double M for good measure, right? Wrong, would argue Lucio Russo, emeritus at Tor Vergata University in Rome, physicist, and historian of science. Arguably, his book could represent the first step towards a worldview where the very idea of a division between the two cultures is essentially inconceivable. In his learned reconstruction of history, Russo shows that the first and essentially the only scientific revolution in human history happened in the third century BC, in the Hellenistic era. The scientific method, together with heliocentrism and atomism, was merely rediscovered by the likes of Copernicus, Galileo, Gassendi, and Newton. The Renaissance was kickstarted by the fall of Constantinople with the ensuing migration of Greek scholars and their books to Italy, where the translators of the time got busy, feverishly rendering their priceless technical content into Latin. From then onwards, all the way to Dedekind’s seminal work on the definition of real numbers in mid nineteenth century Germany, which Dedekind essentially copied from Euclid’s theory of ratios, the ancient languages that are considered the hallmark of the humanities-side of the cultural divide were a tool to access scientific heights otherwise unattainable to the modern man: we are talking here of geometry, which unlocked mapmaking and perspective drawing; atomism, which centuries later blossomed into modern chemistry and statistical mechanics; and -crucially- astronomy.

Second, Russo disabuses us of the notion of an unrelenting, one-directional march of progress of human knowledge. This turns out to be largely an ideological fantasy spearheaded by the intellectuals of the Enlightenment, who quite dishonestly decided to hide their debt to the ancients under a layer of rhetoric. I am looking at you, Voltaire.

As Russo proves, the march of progress is more akin to a random walk than to a straight line. The ancient scientific revolution ended abruptly when the Romans subjugated the hellenistic kingdoms, slaughtering Archimedes and conquering Alexandria, where the invaders put an obscure military officer in charge of the library, dispersing the scholars working there. The technologically and intellectually inferior civilization ensuing in the Roman imperial era was largely unable to recover the lost Greek wisdom, to the point that even the work of Ptolemy is a mere shadow of the hellenistic heights, as Russo convincingly argues.

Another, and perhaps the most important prior that Russo forces us to update, is the idea that mathematics and the empirical sciences are fundamentally different. To the Greeks, they were one. And not for lack of a nuanced understanding of epistemology: to the contrary. Euclid in fact took great pains in his Elements to show how the abstractions whose properties his theoremata illustrate have a real counterpart in the form of a physical drawing, whose guided execution is set forth in the problemata. Does this remind you of the operational definitions of theoretical concepts that articulate the dialectics between experience and reason in experimental science? I thought so too. It was the misguided disciples of Euclid from late antiquity to the modern times that -under the influence of neoplatonism- insisted on separating the supposedly pure, a priori mathematics from the mundane act of drawing, leaving us to wonder how come the abstract, disembodied language of mathematics works so well in describing physical reality.

But let’s start from the start…

Chapters 1-7: Hellenistic science

The forgotten revolution is divided into eleven chapters. The first seven chapters cover Hellenistic science.

The first chapter The birth of science, defines the boundaries of what will be considered science and hence be analyzed in the rest of the book. Russo’s choice to define both the term science and the term Hellenism with surgical precision paves the way for rational, constructive debate, getting terminological confusion out of the way right off the bat.

His setting of the temporal boundaries of the Hellenistic era essentially coincides with largely accepted definitions in history textbooks. The death of Alexander the Great marks the beginning of the period in 334 BC and its end is set about three centuries later in 31 BC with the battle of Actium and the fall of Ptolemaic Egypt under Roman control. Alexander united Greece, Egypt, and large swathes of Middle East and central Asia under his rule, reaching all the way to the western borders of modern China. His empire died with him, leaving a trail of kingdoms in its wake: Egypt, the Seleucid kingdom, Bactria, Pergamon and the Epyrus down to the city-states of Rhodes and Syracuse. This is the civilization Russo’s work is focused on, even though the dearth of documentary material forces him to concentrate mainly on the city of Alexandria with its library and mouseion.

Coming to the definition of science, the author introduces a set of three quite restrictive criteria which, in his intention, capture the common characteristics of disciplines widely accepted as sciences. First, science concerns itself with suitably defined theoretical entities rather than dealing directly with concrete objects; second, the theoretical material has a rigorously deductive structure; third, the applications of science to the real world are based on correspondence rules between theoretical entities and concrete objects. The absence of any of these elements disqualifies a discipline from being considered science, at least for the purposes of the historical analysis carried out in the book. Russo does not advance normative epistemological ambitions, even though the reader is tempted to do so.

It is immediately clear how Russo’s definition is much more restrictive than the etymological meaning of the word science, from the Latin word scientia, knowledge. It is also more restrictive than the notion championed by Karl Popper that a scientific discipline is a set of falsifiable theories. But even more striking than what is left out by Russo’s definition, is what is included in the realm of science: mathematics. Euclidean geometry, for instance, becomes a science in the same league as physics, thanks to correspondence rules that tie abstract geometric entities such as a circle or a segment to actual, concrete drawings.

In light of this definition, it therefore makes sense to ask the question of whether science actually existed at a given time in the context of a particular civilization, such as that of classical Greece (Russo’s answer is no) or ours (his answer is yes -for now). Most importantly, based on Russo’s definition, the Hellenistic civilization was the first to ever do science. This is the cornerstone of the arguments in the first part of the book, which in this way achieves an important goal for historiography as well: to positively identify Hellenism as a civilization characterized by being capable of scientific thought, and not only negatively as the civilization that was no longer Greek and was not yet Roman.

Two subsequent chapters go into the details of various Hellenistic scientific theories, including obviously Euclidean geometry, which was a computational tool leveraged by other sciences -hence the insistence on compass and straightedge constructions: one could use this kind of drawing as an analog computer. Unlike other Hellenistic authors, Euclid has been handed down to us relatively seamlessly, which makes it possible for a modern reader to appreciate the importance of a mathematical theory characterized by a rigorous deductive structure based on a minimal set of fixed axioms. This means proving one by one all the relevant propositions of the theory, even the trivial or self-evident ones. Russo contrasts this with earlier geometric ‘proofs’ that took for granted any statement that appeared self-evident by looking at a drawing, as the famous one reported in Plato’s Meno.

Still in the realm of geometry, Russo shows how the Greeks mastered infinitesimal methods by reproducing Archimedes calculation of the surface area of a parabolic segment, which is in essence an integral. He then moves on to other theories, such as optics, on which an elaborate theory of perspective was based: Pappus of Alexandria, commenting on Euclid’s Optics, discusses the concept of vanishing point. He discusses the theoretical notion of a "visual ray" coming out of the eye, which is the object of mathematical theorems in Euclidean optics, and is intended to model, among other phenomena, the limited resolution of what we can see at a distance. The famous hydrostatics of Archimedes is organized similarly to geometry in a deductive structure, and what we today call Archimedes principle was actually a theorem. Further, Russo covers geography, mechanics, hydraulics, pneumatics, astronomy (including heliocentric theory) in a wealth of detail that we cannot summarize here.

The following chapters deal with disciplines that do not qualify as sciences according to Russo’s definition, but are related to the main core of Hellenistic science. Chapter 4 covers scientific technology, that is technology that is made possible by relevant scientific knowledge. By design, the axiomatic-deductive method allows theory to be pushed beyond the boundaries of what can be understood by the passive observation of nature. Scientific theory becomes a tool for predicting the behavior of artificial systems, of which no previous experience was available through the mere observation of nature. Tellingly, the original meaning of the Greek word mēkhanikḗ is science of the machines. Material remains of the Hellenistic technical developments are widespread, and have often prompted considerable curiosity in the wider archaeological community, especially given the fact that the scope of Hellenistic technological prowess is largely underestimated.

Chapter five covers the medical-empirical sciences, which do not admit the construction of exact mathematical models. The author here tells us about Herophilus of Chalcedon and his adventures in the field of medicine and the biology of the human body. He is shown to have an experimental approach, based on dissecting cadavers and experimenting on living humans - typically slaves or prisoners. Russo points out how these sciences lead to the introduction of new terms which were deliberate neologisms, for instance in the field of anatomy. This form of linguistic conventionalism was unknown in classical Greece. Having reached this point, Russo makes us fully appreciate the importance of the concept of theoretical model in scientific knowledge, even outside of its immediate scope of applicability. Scientific model making promotes a methodological unity that rejects the naive concepts of true and false, concentrating rather on the notion of a useful or useless model. The development of conventional terminology for the new empirical sciences, which got rid of the idea that words have intrinsic meanings by treating them as mere symbols, was likely influenced by this new epistemological point of view.

Chapters 8-11: Decadence, the end and rediscovery of science

The last set of chapters abandons the historical treatment of Hellenistic society and is devoted to the study of what happened next. In summary, the thesis is as follows: the Roman conquest of Egypt and in short order of the entire Hellenistic world marks the end of ancient science. Roman civilization was essentially still at the pre-scientific stage, and Roman rule undermined the subtle social alchemy that had enabled the creation and transmission of knowledge. As there were no longer scholars able to understand scientific theories and teach them, books soon became essentially incomprehensible, and were lost or forgotten. The imperial-era accounts written by Latin authors about Hellenistic science are clear evidence of this: these authors understood little of what had been produced before them. For instance, while in the Hellenistic age it had been pointed out that bees produce hexagonal cells because of all the regular shapes hexagons use the least amount of wax, Pliny tells us that bees produce hexagonal cells because they have six legs. What will condition the centuries to come, however, is the loss of the concept of theoretical model. Mathematical entities and mathematical demonstrations will continue to be (more or less) understood, but their meaning will be misrepresented: the rules of correspondence between the real and the abstract will be lost and theoretical entities will be reified. It will not be until the dawn of the modern scientific revolution that bits and pieces of the nimble epistemological mindset of the ancients will be recovered, albeit shrouded in an awkward melange of neoplatonic philosophy and Christian theology -as is the case in Newton.

We found Chapter 8 ‘lost dynamics and astronomy’ extremely interesting despite being the most speculative. Here the author leverages his knowledge of natural phenomena as described by contemporary physics to bridge the many gaps in the written tradition that reached us. Many -elsewhere Russo ventures a figure of 98%- of the original texts have been lost, and especially the technical ones that became incomprehensible in the Roman era; nevertheless, we are in possession of numerous later texts that tell us the content of the lost works. These texts have misrepresented the content, and they are unreliable. But we know what they were talking about and Russo loves to read between the lines: in the light of this, it is possible to reconstruct the content of the lost science like dinosaurs are reconstructed from incomplete skeletons.

The author offers many examples. Perhaps the most accessible are those related to heliocentrism and the theories of gravitation. Indeed, we know that Aristarchus had developed a heliocentric theory, but we do not know much more. Russo proposes interpretations of the texts of Plutarch and other Roman authors that are absolutely shocking and would lead one to believe that a real theory of dynamics existed in the Hellenistic world.

It will suffice here to cite an excerpt he reports from Plutarch’s book de facie quae in orbe lunae apparet: certainly the Moon is prevented from falling by virtue of its rapid rotating motion, like an object placed in a sling is prevented from falling by its circular motion. Every body undergoes natural motion unless it is deviated by something else. So the Moon does not follow its weight, which is counterbalanced by the effect of rotation. (our translation from Russo’s Italian version). From here, Russo proceeds to discuss the concept of forá, which he renders in his own translation as trascinamento (drift), arguing that it is essentially equivalent to the modern concept of centripetal acceleration.

The book ends with the story of how Hellenistic knowledge was recovered in modern times, even though perhaps not in full.