Unpredictable novelties

The natural world is a hierarchy consisting of several layers beginning with subatomic particles and ending in the ecosystem, according to new thinking

Convergence is profoundly simple and simply profound – and possibly the most important book you’ll read this year. On one level, Watson eloquently demonstrates how the sciences overlap, converge and support each other, so “discoveries in one science can quickly lead to advances elsewhere”. More fundamentally, he argues that there is “an emerging order – a convergence, even a kind of unity – between the sciences” and that “this order or unity” gives science “an authority unrivalled among other forms” of knowledge. Despite the seeming complexity and chaos of the world around us, the “deep order” revealed by science is “so strong” and “so coherent” that it is beginning to impinge on philosophy, morality, history, culture and politics. In other words, the implications of convergence go far beyond the laboratory bench.

Watson marshals examples from disciplines as diverse as quantum mechanics, dendrochronology and child psychology. For instance, the principle of conservation of energy – a foundation of modern physics proposed in the 1850s – brought together insights from heat, optics, electricity, magnetism, food and blood chemistry. Darwin’s theory of evolution rested intellectually on elements drawn from deep-space astronomy, deep-time geology, palæontology, anthropology, geography and biology. And Watson brings the discussion up to date with cutting-edge examples. Convergence, for example, eloquently examines the tension and inter-relationship between reductionism and emergence.

Reductionists break complex phenomena into more fundamental constituents. Reductionism, for example, allows physicists to characterise the Higgs Boson and other elementary particles, and offers molecular biologists an unprecedented understanding of the pathways inside our cells that are essential for our health and wellbeing. It allowed pharmacologists to develop important new drugs for cancer and other serious diseases.

Yet reductionism doesn’t tell the whole story. As Srdjan Kesic comments in an insightful recent paper ( Saudi Journal of Biological Sciences 2016;23:584–591): “It would be impossible to explain the functioning of a biological organism using only physicochemical principles”. The newer idea of ‘emergence’ aims to addresses these concerns by assuming that the natural world is a hierarchy consisting of several levels beginning with subatomic particles and ending in the ecosystem, biosphere and so on. Each level, Watson notes, has certain “unpredictable novelties” – such as mental functions, consciousness and life – that do not appear in, and cannot be predicted from, the lower levels. It’s important to recognise that these emergent properties do not break the laws of physics. Rather emergence adds layers that are as fundamental as those below in the hierarchy.

Increasingly, however, understanding individual layers – let alone the interactions between them – involves some fairly sophisticated mathematics. Analogies (such as visualising the curve of space-time as the skin of a balloon) can aid understanding. But, sadly, the increasing reliance on mathematics will increase the divide between science and the public – as well as, I suspect, between disciplines. I can, usually, cope with the statistics and mathematical models used in my discipline, biology, but I don’t pretend to grasp the mathematical basis of quantum mechanics. That’s one reason why accessible books such as Convergence are so important to the general public and for other scientists.

Fundamentally, I suspect a convergence forged through reductionism and emergence will eventually emerge across the sciences – but it will be a longtime coming. As Watson notes, some critics suggest that certain sciences (electronics and cultural anthropology, for example) are too far apart to allow any meaningful convergence. Of course, scientists will be able to use emergence and reductionism to gain insights and make technological advances. But true coherence between, for example, the physics of how a laser plays a CD and why I chose to listen to Slayer’s ‘Repentless’ while I wrote this, won’t, I suspect, happen in the foreseeable future. Some fundamental issues withstand both reductionism and emergence. We can’t, for example, understand consciousness from the interaction of nerves and chemicals, let alone fundamental particles. Indeed, Paul Verschure commented recently that “understanding the nature of consciousness is one of the grand outstanding scientific challenges”. One fundamental problem, he notes, is developing a verifiable means for observers to assess someone else’s subjective experiences ( Philosophical Transactions of the Royal Society B: Biological Sciences 2016;371:20150448). I’m sure we’ll soon model consciousness in an analogous way to how we model life and be able to define consciousness and life in operational terms. We won’t, I suspect, capture the essence of consciousness and life – and reach accepted definitive definitions of either – in my lifetime.

Meanwhile, science is attacking bastions that were once preserves of philosophy, religions and poetry, which raises important ethical concerns. Genetic advances raise the prospect of parents choosing their child’s characteristics – which could involve traits that are passed on to future generations. Watson notes that such advances raise important questions. What will this do to our sense of being? Will people become things rather than beings? Will this challenge

“In other words, the implications of convergence go far beyond the laboratory bench”