Feynman once defended science from an artist-friend who claimed aesthetic appreciation of the beauty of a flower seemed superior to (mere) scientific understanding; Feynman replied that his knowledge of science in no way subtracted from the beauty of the flower, nor his appreciation of it. Indeed it is sometimes an unspoken, and unjustified, assumption that the same rationality that fuels the scientific endeavour costs the scientist an otherwise magical connection to the cosmos. Ian Glynn however, makes a stunning and compelling riposte in his book, Elegance in Science.

To clarify, the word elegance in the title of the book is quickly divorced from its colloquial definitions; it is not strictly a matter of grace or taste. Rather, elegance in science is an idea described or an experiment designed with a stoic understatedness reminiscent of Zen minimalism and the information density of Occam’s Razor explanations. For example, the book cites a cognitive illusion (in the same sense as optical illusion) designed by Vilayanur Ramachandran, one of the foremost neuroscientists of our time.

Consider a black-and-white image above with what appears to be bumps (curving outward or inward). Now when the image is rotated 180 degrees, the brain switches the bumps; what were previously considered to be protruding outwards now seem to be hollows, and vice versa. This optical illusion illustrates how human perception is unconsciously influenced by pattern-matching; while the bumps and hollows are never explicitly identified as such, the common occurrence of global illumination coming from above is unspoken yet implicitly assumed.

Why is this elegant, one may ask. Well, a complex hypothesis — that perception is not purely real-time and without bias — has been conclusively tested and demonstrated with little more than a small black-and-white image. The brilliance of this experiment is equally in its hypothesis as it is in its almost-poetic economy. Yes, elegance in science is a lot like poetry in literature.

The structure of the book is delightfully ambitious. Each chapter details fundamental advances in a single branch of science, following the insights and deductions of scientists through the ages. The first chapter for instance starts with Ptolemy’s observations of the night sky, brings in Copernicus, Galileo & Kepler jointly expanding on the intricate motion of the celestial bodies, finally inviting Newton to tie up the theory of gravity. It is novel and enjoyable to see science presented in such a historical narrative context; the retelling of meticulous experiments that ingeniously transcend the social and technological limitations of their time only serve to offer the reader a voyeur’s view of genius at work.

And genius is not a word I use lightly! There is something almost heroic about the great personalities, some even polymaths, who have advanced science in fundamental ways. In a prevalent culture that would rather poke fun at genius for not being normal (see Big Bang Theory), it is heartening to hear of the exploits of original thinkers, and also saddening to realise the majority of my peers will not appreciate the sheer anomalous brilliance that these luminaries have shown. Indeed I recall a sardonic quip that went: ‘the gap between thinkers like Socrates & Nietzsche compared to the average man is greater than the gap between the average man and a chimpanzee’.

The book moves swiftly along, the following chapters laying out the path of the other fundamental phenomena like heat and light to the illumination of science. And yet there is constant reference at every turn to the discoveries and inventions of earlier thinkers, lending empirical credence to Newton’s famous words, “I stand on the shoulders of giants.” Indeed, Science is not just a school of thought, it is a family of thinkers. By the time the reader finishes the final chapter which masterfully spins the tale of how the structure and mechanism of DNA was revealed to science, a tale more than two centuries in the making with guest appearances by Darwin himself, it is not easy to mask the astonishment at the grit of scientists and the pace of scientific progress. From Gregor Mendel’s innocuous experiments with pea plants revealing the method behind the madness of heredity, to Thomas Morgan’s pioneering work with fruit flies entering Drosophilia into popular lexicon, to Oswald Avery’s deductive experiments that isolated DNA as the carrier molecule of genetic information, the snowballing insights enabled Watson & Crick to arrive at their Nobel Prize-winning work on the structure of DNA.

Elegance in Science is indeed an erudite book, a must-read for anyone who fails to see the romance in science. However, it does not dwell on why elegance, an aesthetic criterion, should even be a consideration as much as revel in the ingenuity of the scientists and their experiments. Is elegance a coincidence when considering an important scientific theory, or perhaps an added bonus? This is the central question addressed by James McAllistair’s Beauty and Revolution in Science, which adds an extra dimension to the insights so far.

According to McAllister, what Ian Glynn calls elegance falls under a broader intuition of aesthetics and beauty. To date, no one explanation has managed to capture what beauty is, or what it means for that matter, which relegates the word into the realm of poetic subjectivity. How then can any self-respecting scientist claim the superior merits of a theory (or experiment to a lesser degree) on the basis of its elegance? After all, one of the prevailing models of the scientific enterprise is captured in the tenets of the “logico-empiricial model” — a set of precepts that can be used to assess the strength of scientific theories. These are:

1. the criterion of consistency with existing empirical data

2. the criterion of novel prediction

3. the criterion of consistency with other existing theories

4. the criterion of explanatory power

5. the criterion of empirical content, and

6. the criterion of internal consistency

Every scientific theory advanced thus far can and should at least satisfy these criteria to be considered a viable candidate to explain and explore natural phenomena. However, these criteria alone do not seem to even hint at the predilection scientists have to pass aesthetic judgement on one theory over another. Neither do these criteria explain why scientific revolutions happen, wherein the fundamental narratives for theory assessment are radically restructured. If the logico-empirical model were founded firmly on the notion of “empirical adequacy of theories”, then these theories should hold true before and after a scientific revolution equally well but they do not.

McAllister rightly questions then if the logico-empirical model alone is enough to explain the notion of beauty and the legacy of revolutions in the history of science.

Before we answer that question, we must revisit the definition of elegance, or beauty, or any similar notion of aesthetic quality as applied to a scientific theory. McAllistair clearly defines beauty to be a perception (by a sympathetic and appreciative perceiver) rather than a property (of the object in question), in essence echoing the adage “beauty is in the eye of the beholder”. This is immediately worrisome, because it only makes beauty as a criterion even more subjective, and not at all amenable to the rigor demanded by the logico-empirical model of scientific enquiry. If that were not enough, the beauty of a theory is more often than not conflated with the measure of truth it conveys, even by and especially within the scientific community. As much as the aesthetic sense is pleasantly tickled by one theory over another, it almost sounds heretical to base sound science on the basis of perceived beauty. Does the aesthetic consideration precede or supersede empirical rigour, when debating the merits of a theory?

In McAllister’s construction of the scientific enterprise, he extends the notion of aesthetics into a narrative that supplements, or at least complements, the logico-empirical model of science. In essence, he establishes that an aesthetic canon in the scientific community builds cumulatively with every internally-consistent theory that agrees with other existing theories. By aesthetic canon, he means that an existing framework is accepted as beautiful, and scientists trained in the context of this framework are likely to accept theories that agree with the framework as beautiful. New theories that build on existing, well-established and well-regarded theories are accepted easily by the community. The greater the successful track record of the framework and the related set of theories, the more the influence and weight they wield in the community, the more strongly that these theories are perceived to be elegant and beautiful. Recall that McAllister defined beauty as a perception, not a property, of scientific theories. Thus he posits the perception of beauty is cumulatively assigned to a set of theories over time as more and more scientists project their aesthetic appreciation onto that scientific framework, rendering that framework more and more beautiful in perception.

To fit within the logico-empirical model, this elegance of theories has some rational qualities, summarised by Weinberg as the following: conceptual simplicity, logical completeness & consistent symmetry. In time, new theories are accepted not purely on the basis of empirical adequacy but also their aesthetic compatibility with the existing framework. McAllister calls this process of legitimising the aesthetic sense of a set of theories “aesthetic induction”. The aesthetic induction eventually becomes at least as important a criterion as empirical adequacy in theory assessment.

This could be a plausible construction, were it not for the fact that science is oftentimes shaken up by radical restructuring, when new experiments or observations upend the traditional views held as sacrosanct till then. Revolutions have been a testament to the unbiased nature of scientific enquiry. But this also means that the aesthetic canon held so far is violently replaced, in favour of a new nascent era of what aesthetics should mean to science. Does this mean that aesthetics is confirmed to be a subjective criterion, not worthy of employing in theory assessment?

McAllister weaves even scientific revolutions into a meta-narrative revolving around the very notion of aesthetics. In times of non-revolution, the empirical criteria for theory choice are congruent with the aesthetic criteria for theory choice, as per the definition of aesthetic canon, which accords greater aesthetic priority for the frameworks that resiliently stand the test to time (since the last revolution at least).

However, when new results challenge the prevailing theories (and therefore the underlying aesthetic canon), there is what he calls an “aesthetic rupture”, wherein the scientific community is divided by support for the (aesthetic) legacy of the old framework and desire for a new framework that can explain at least explain the new phenomena empirically what the old framework cannot. That is to say, the empirical criteria for theory choice (the call for empirical adequacy to explain the new anomalous results in the single framework that still explains all prior phenomena) diverge significantly from the aesthetic criteria for theory choice (which are derived from the combined aesthetic and empirical legacy of the existing framework). The cognitive dissonance of aesthetic rupture is thus posited as being at the heart of scientific revolutions!
Indeed, this is a sophisticated argument for the appreciation of aesthetics in scientific theories, even self-perpetuating in a sense, because it is this very sense for aesthetic compatibility as opposed to pure empirical compatibility, in McAllister’s view, that brings about scientific revolutions that keep every field advancing as it should.

However, I am not entirely convinced of this line of argumentation, clever as it may be. In my opinion, the scientific method hails at least in part from the philosophy of empiricism, and indeed revolutions in science are a testament to the prevention of bias in the study of science. To claim an “aesthetic canon” builds up (merely) on the basis of reliability of the body of theories over a period of time firstly demeans the more profound sentiment expressed by scientists when referring to the beauty of a theory.

Brian Greene eloquently argues that to him, the beauty of an equation is perceived when the realisation strikes that the simple mathematical relations explain such a broad range of real-world phenomena; the broader the implications, the more elegant is the perception of that equation. When Brian Greene waxes lyrical about the ability of a single equation (in string theory) to explain every interaction that occurs in the universe, and thus imparting a sense of awe and the perception of beauty, that is not a sentiment that is derived exclusively from peer pressure and statistical reliability as McAllister’s “aesthetic canon” would imply.

Of course, this would be refuted with McAllisterian view that Brian Greene’s appreciation of string theory’s aesthetics is the direct result of his marination in the prevailing frameworks of the time, leading him to conceive of string theory as aesthetically elegant. However the example of string theory is very useful in this case — here is a theory that is relatively new, has been hailed as aesthetic owing to its mathematical properties, able to explain existing phenomena but itself remaining untestable, and largely without empirical evidence owing to the infinitesimal scales and the enormous energies such experiments would demand. By McAllister’s construction of the aesthetic canon, string theory occupies a strange limbo at best, seeing that it does not have any empirical legacy to its name (yet) and still is hailed as elegant, too elegant to be true for its cynics. This exposes a single flaw in McAllister’s reasoning, that an empirical track record, and consequently an aesthetic canon, is required to have a sense of aesthetic appreciation. Only time will tell ultimately if string theory will serve as the backbone for an arguably revolutionary Theory of Everything, but it is clear even now that aesthetic rupture will not be the reason for its adoption or demise.

To clarify, I can appreciate that McAllister’s mechanism of aesthetic induction plays some role, but would disagree as to that being the only acceptable definition of aesthetics and to the extent of its influence.

Consider Thomas Young’s famous double-slit experiment, demonstrated with not much more than a candle, two slits and a screen that light was (also) a wave. At the time, Newton’s particle theory of light was so dominant, thanks in no small part to Newton’s stature in the scientific world, that Thomas Young’s work which opposed the Newtonian view of light was given little attention, if not caustic remarks. However, so impressed was fellow scientist Sir John Herschel that he wrote [italics-emphasis mine]: “… with the elegant, simple, and comprehensive theory of Young— a theory which, if not founded in nature, is certainly one of the happiest fictions that the genius of man has invented to group together natural phenomena… insomuch that we may be almost induced to say, if it be not true, it deserves to be so.” Perhaps Thomas Young’s experiment did not cause a scientific revolution by means of an aesthetic rupture, it must be noted that it was aesthetically displeasing to the scientific community at the time. Therefore I hold that this sentiment of Herschel’s is even more telling of the prized evaluation of aesthetics in science — that the appreciation of the beauty of a theory or an experiment is not limited by the aesthetic canon of its time.

Can the McAllisterian view write off the Thomas Young example? And to what end — why is it important to establish aesthetic rupture as the only type of revolution ever possible?

In his own words, McAllister says “a revolutionary theory is one that attracts support on the strength of its empirical performance and opposition in virtue of its aesthetic properties”. Moreover, he continues that “a theory that falls short of revolutionary attracts support on the strength of its aesthetic properties, whatever effect its empirical performance has on its reception”. This is the notion I have quite some trouble digesting. Firstly, is the reader supposed to accept wholesale McAllister’s arbitrary classification of what is revolutionary? Secondly, why is this definition the only definition of revolutionary? While the author can appreciate the mechanism of aesthetic induction as a plausible cause of scientific revolutions, it is at best one cause of scientific revolution from the perspective of one set of criteria, namely the aesthetic one.

McAllister himself references aesthetic rupture in the applied arts, citing the problematic adoption of iron as an architectural material, since it was seen as functional by the engineers (empirically) but unaesthetic by architects (operating under the aesthetic canon that exalted masonry). While the author can appreciate the (cherrypicked) example that is amenable to McAllister’s construction, it seems distasteful to argue that the choice of iron over stone in architecture is a bona fide revolution in a way Einstein’s cosmological notion of space-time is not. The logical and imaginative leap in considering what it would be like to move at the speed of light and its implications for space and time is such a lofty thought for a single mind to wrap its head around, let alone so original when it was first contemplated, that indeed it is aesthetically blasphemous (by my personal aesthetic canon) to be judged inferior and less revolutionary than deciding if iron should be used in architecture despite knowing of the empirically superior strength of iron all along.

Fundamentally, my skepticism is borne on two premises that have not been convincingly argued away by McAllister, namely:

1. The sense of aesthetics can be independent of rationality, even among scientists. A non-rational notion of aesthetics does not hurt the scientific enterprise so much so that it must be rejected .

2. There can be some rational aspects to the aesthetic sense that scientists espouse, but not necessary that aesthetic sense as a whole must be rational, or be deemed invalid as a criterion otherwise.

And this skepticism is the author’s (automatic) defense to McAllister’s gross irreverence for the role of imagination, creativity and daring (all intangible, all non-empirical) in his construction of aesthetics as a purely rationalist criterion. A scientist is not obligated to give up enjoyment of a fine wine or a fine woman in a way that cannot be put into an empirical equation. Why then should a scientist not espouse preferential aesthetics towards fine work?

To say Copernicus is less revolutionary than Kepler is almost dishonest — if Copernicus’ circular orbits were shortcomings, so was Kepler’s (earlier) predilection for conjecturing symmetrical polyhedra within the orbits. If Kepler’s elliptical orbits theory was revolutionary, it was only on the basis of Copernicus’ heliocentrism combined with Tycho Brahe’s meticulous almanac of planetary positions. Kepler’s empirical revolution in no way diminishes Copernicus’ ideological heresy of his time.

Similarly Niels Bohr’s empirical contributions to quantum mechanics in no way diminish the imaginative heights of Einstein’s thought experiments. Ian Glynn would undoubtedly give Einstein his due credit for interpreting a complex equation in so succinct a notion as the “fabric of space-time”, identifying the elegance of the theory in its deceptive simplicity.

Note that this is not to say the author rejects the social constructivist narrative of the aesthetic canon at a broad stroke, for it is undeniable that indeed the cultural environment surrounding the scientific community, or even within the scientific community, plays a large role in shaping which theories are deemed acceptable, or for that matter, aesthetic. The Copernican Principle was considered blasphemous in the religious climate of its time. The Darwinian theory of natural selection was seen as an obvious affront to the nobility and superiority of Man, given the Victorian sensibilities that surrounded science at the time. In my view, a revolutionary idea can satisfy the requirements of revolution on more grounds than just the empirical-aesthetic axes, for instance by advancing a perspective that no one else has considered before.

Even so, McAllister’s work still captures the great reverence for elegance and beauty in the pursuit and philosophy of science. Beauty and Revolution in Science is a insightful journey, exploring the role of aesthetics in the scientific method, and questioning whether it should be used at all, and if so, how. In combination, the two books present a more nuanced way to look at science.

If we were to revisit Ian Glynn’s Elegance in Science, armed with an updated definition of beauty and truth, we see the economy of the experiments described in a whole new light. Consider again Young’s double-slit experiment. The monumental insight afforded by the outcome is seemingly magnified by the simplicity of the experiment. The beauty of this experiment is not appreciated in its entirety, without simultaneously being aware of the precedent prevailing theories, the available technologies at the time, and the radical implications of the confounding result. This lends credence to McAllister’s definition of beauty in science being a perception rather than a property.

However, the sheer elegance of it was so overwhelmingly convincing that an otherwise mind-boggling conclusion, that light is both a particle and a wave, is accepted without much ado. McAllister’s construction of aesthetic canon being challenged leading to aesthetic rupture (and thus a revolution) is not evident here. It is the author’s continuing belief that revolution in science does not follow automatically from a deviation from aesthetic canon. Furthermore it is the author’s view that revolution in science is not always defined and precipitated by aesthetic rupture.

One thing that stands out more than ever, in the reading of the books, is the realisation that the greatest thing Science has ever offered mankind is not fact, but experiment. Be it the ingenious attempts of Thomas Young to establish light as either a wave or a particle, or the fact that this experiment was foundational to some of Einstein’s theories and similarly foundational to quantum mechanics which Einstein could not easily digest, the prevailing opinions and theories may have changed drastically but the simple experiment itself was infallible. This insight, now more than ever, puts Science in perspective.

Indeed, as Ian Glynn’s Elegance in Science illustrates, through the centuries, it is through the power of experiment that progress has been made, time and time again. This too leads me to another startling insight. Other than the ingenuity of designing, nay inventing, new experiments, scientists advance the other remarkable tool in the scientific method, the hypothesis. Why are hypotheses important? To hypothesise is to suggest a mechanism linking cause and effect; it suggests that every phenomenon can be explained logically, systematically and most importantly, reproducibly. Indeed it would be reasonable to say that hypothesis and experiment are related the same way science and technology are related. And so, (technological) progress can be seen to be inevitable when proceeding with the scientific method.

And finally, McAllister’s Beauty and Revolution in Science imparts a reverence for aesthetics in science to a degree, and a greater degree, respect for the philosophy of science. Indeed it is only through the lens of philosophy of science that an otherwise shallow criterion like the importance of perceived elegance of scientific theories, in this case, could be critically examined, dissected and validated. And in so doing, the validity (or the bias) in the scientific method is elucidated, improving the scientific method in a holistic manner, i.e. not just technically and theoretically, but also ethically and epistemologically.