What We Cannot Know: Explorations at the Edge of Knowledge by Marcus du Sautoy
My rating: 4 of 5 stars

Stories For the Widening Gaps

I was educated in the school of anti-reductionism. That is, I was taught that knowledge of how the fundamental particles of the universe work would not help me understand what I might choose for dinner. I did take university courses in physics and chemistry, but the deterministic implications of science, those which suggested the fictional character of things like purpose and choice and free will, were never allowed to surface fully. It turns out that my views may simply be the result of never having encountered a literate reductionist. Marcus du Sautoy is such a literate reductionist. And I am tempted to rebel at an advanced age against my upbringing.

The classic objection to scientific reductionism - the idea that the world works strictly according to fixed laws of cause and effect - is that it can’t explain science and other apparently purposeful activities. But it turns out that there are good scientific reasons for this. The complexities of scientific thought, actually any thought, are so great that although its physics are deterministic - in the manner of billiard balls on green felt - its trajectory cannot be predicted. We cannot know either the starting point of the billiard balls or their random quantum connections.

It is this complexity, not any extraneous properties like spirit, or intelligence, or God, that leads, deterministically, to our stories about some substances other than energy and matter as important to human life. Properties that appear ‘emergent’ are simply those whose complexity we cannot (yet) penetrate. Our narratives of human motivation, character, and responsibility merely fill in the explanatory and predictive gaps created by this emergent complexity.

Interestingly, these gaps increase as science progresses. More knowledge about the world increases our understanding of its complexity even as we simplify our theoretical descriptions. Every scientific advance multiplies the number of unsolved scientific problems. What du Sautoy (and Donald Rumsfeld) calls the known unknowns blossom exponentially. But rather than project philosophical or theological narratives into these expanding gaps, we can only throw more science. The narratives that science supplies may be less literate but they are certainly more compelling. Human thought, it appears, becomes simultaneously more inclusive and less certain but yet more confident as it develops.

I admire this implication. It is a humbling observation that we are not exempt from the materiality of the rest of the universe. The exceptionalism of humanity in its own mind has been the cause of much misery. Everything we know is uncertain. Kant, it appears has been vindicated - we can never even hope to know the universe as it is. Yet we can have confidence in our scientific narratives because... well because they provide something for which to hope. This hope is not one of personal salvation, or the coming of some other universe but one of realizing human harmony with the universe as it exists. This, I think, is the principle ethical content of modern physics: that there is an inescapable necessity to conform, even when we believe we are rebelling.

Traditionally, ethics have been grounded in one’s view of anthropology. Some believe that appropriate human behaviour can be deduced from the necessities for survival; others that there are divinely mandated rules for conduct. What du Sautoy’s scientific narrative suggests is that this anthropological view is arbitrary in terms of both its level of analysis as well as its presumptions about what it means to be human. Why not a ‘fundamental particulate’ ethics? And why not a complete abrogation of any fixed, final definition of what these fundamental particles might be? This approach would suggest that the search for what it means to be human is the real ethical task, a task which should never result in dogma that is purported to be certain.

It could be that my sympathy for du Sautoy’s account is prompted by his own sympathy for Plato over Aristotle - an attitude roughly equivalent to a psycho-analyst preferring Jung to Freud. Du Sautoy quotes Werner Heisenberg approvingly: ‘Modern physics has definitely decided in favour of Plato. In fact, the smallest units of matter are not physical objects in the ordinary sense; they are forms, ideas which can be expressed unambiguously only in mathematical language.’ So then, science, art and philosophy appear as random variants of the same deterministic trajectory. We can’t seem to stop ourselves from doing the same thing - telling stories - in different ways.

All sorts of criteria for verifying science - or for preferring Plato over Aristotle - have been used historically: simplicity, elegance, statistical correlation, logical implication, and tradition, among many others. The criteria are as unstable as the results of science itself, and they vary among disciplines and are differentially favoured by individual scientists within disciplines. It doesn’t take much insight to recognize what du Sautoy admits: the criteria of scientific analysis are unavoidably aesthetic; they correspond to what we find beautiful. Beauty may be correlated with things like usefulness and consistency in evolutionary terms but it nevertheless stands alone as the proximate cause of scientific action.

So the stories we tell ourselves are better or worse not by any objective standard but by the inherent arbitrariness and subjectivity of our appreciation of what constitutes the beautiful. Our nervous systems are even apparently constructed so as to provide illusions when confronted with incoherence. Having said that, it is clear that beauty is not entirely arbitrary or subjective. Beauty is something we are taught, like language. It may appear that certain forms or ideas are ‘obviously’ more beautiful than others but only because there is no challenge to them within our social group.

Science, it seems, is the evolved social institution in which just this debate about aesthetic criteria must take place. And the historical narrative of science is one of continuous instability, a story of changing fashion and taste. This, not some fixed standard, is what we mean by ‘reason’ - intense but non-violent argument about how to argue. The content of reason, its meaning, varies more or less continuously. Any attempt to halt the evolution of reason - by religious authority or governmental dictate - will therefore ultimately fail as unreasonable.

Could it be that the narratives of continuity that we tell ourselves - of personality, of memory, of culture, of history - are mere gap-filling? Having disposed of God as the explanation for what we find inexplicable, we seem to rely even more heavily on stories about ourselves - psychological, behavioural, even spiritual stories that have the same function as the old fashioned religious narratives: providing comforting continuity. These stories may be put forward as scientific but are they anything but pseudo-science in their insistence as being ‘truthful’ given that they cannot account for the fundamental discontinuities of our existence? Scientific determinism, therefore, has an unexpected effect - it opens the world to change, innovation, surprise, even opportunity, particularly the opportunity to create new stories.

I feel a certain satisfaction in the uncertainty created by this conclusion. And it gives me some comfort as well. In a way, it seems to me, recent science frees story telling, and therefore all of literature, from the stigma of ‘fiction’. What is the distinguishing mark of science other than its unconstrained swapping of stories? The fact that we can’t know anything definitively, neither the length of the hypotenuse of a right triangle of unit size, nor the character of a photon, means, perhaps, that we have evolved randomly precisely in order to produce and exchange fictions. Jorge Luis Borges would probably be pleased. And Adam Levin in his novel of spiritual determinism, The Instructions, provides a rather apt summary of the situation: “It is good to do justice because God will kill you and your family whether you do justice or not.”

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