On the Equality of All Things by Carlo Rovelli review – a physicist’s guide to life, the universe and everything

Under the letter “B” in the index at the back of Carlo Rovelli’s latest book you will find Francis Bacon, bats, behaviourism, Henri Bergson, and the big bang. This intriguing little miscellany reflects the sweeping ambition of what is perhaps Rovelli’s most overtly philosophical work to date.

Rovelli, who directs a quantum gravity research group in Marseille, has written several books on physics for the general reader, including the global bestseller Seven Brief Lessons on Physics. His latest is an attempt to integrate principles and theories from the discipline into a broader Weltanschauung: one of the essential unity of all things, and the profoundly relational and perspectival nature of the universe. “Electrons and minds, stones and laws, judgments and galaxies do not essentially differ in nature from one another,” he writes. “They are notions that illuminate each other.”

If this sounds familiar, that’s because it is. Rovelli echoes concepts that have been around for millennia in ancient thought, including Hinduism and Buddhism, from whose sacred texts he quotes. But what sets him apart from the countless other modern writers, dreamers and thinkers who preach the oneness of it all is that he grounds his ideas in scientific theory rather than theology or new age conjecture.

On the Equality of All Things is a slender volume holding an extraordinary density of ideas. Translator Simon Carnell, himself a poet, maintains the clarity and concision we have come to expect from Rovelli’s writing. In six chapters, or “lessons”, Rovelli lays out the philosophical significance of what he believes is a major scientific revolution, happening right now. The first lesson refers to his theory of relational quantum mechanics to ask us to abandon the notion that the world is made up of things with fixed properties. Rather, physical systems have properties relative to other physical systems. Also, everything’s moving, all the time, and there’s no fixed point around which we are in motion.

The second lesson takes aim at the idea of linearity. Rovelli urges us to accept circularity and question the need to identify the ultimate foundation of things, when in fact, it’s turtles all the way down. The lessons continue. The world is not made up of things at all, but processes. “Even a stone is a process”, and so are we. Time itself is mutable and passes at different speeds in different places. Our knowledge of anything can only ever be partial.

It’s enough to give you vertigo, and Rovelli admits it. “The resulting image of reality is haunting. Every fact is only a fact relative to something else, and even the fact that a fact is relative to something else is itself relative. There is no ground floor.” Yet, in contrast to the bleakness that can shroud such unflinching scientific accounts of the universe, Rovelli’s telling validates our messy, subjective human experiences. “None of this prevents us from describing the world from one perspective. Ours.” But the physics tells us that our perspectives are just that, and that there may be others.

On the Equality of All Things takes its place as part of a blossoming movement that asks us to see the world as a set of interconnected relationships. As such, it sits alongside the work of mycologist Merlin Sheldrake, botanist Robin Wall Kimmerer, physiologist Denis Noble and nature writer Robert Macfarlane. Rovelli’s emphasis on perspective and relationality in physics echoes similar intellectual turns in social anthropology, ecology and biology that invite us to stop thinking about the world as something we stand without, and instead take our rightful place within it. Distancing himself from the more hubristic elements of the Enlightenment – an emphasis on certainty, linearity, and overconfidence in the imperfect instrument that is Reason – Rovelli asks us to embrace “the nimble lightness of circularity, complexity, ambiguity, metaphors, emotions, the acceptance of uncertainty and change”.

His refusal to denigrate human culture as being inferior to or incompatible with hard science is refreshing. He observes wryly that the term “consciousness” has superseded the word “soul” because it is perceived to be more scientific, even though it is just as nebulous. Provided we understand that physical processes underlie everything, Rovelli sees no reason why we may not “calmly speak of the soul and emotions just as we speak of tables even if tables are collections of atoms”.

For all Rovelli is a gifted communicator, some of the science in this book required a level of intellectual scaffolding that, alas, my rusty physics A-level did not provide. At his explanation of loop quantum gravity, my brain started to creak and let off steam. Yet, even if you don’t have the foggiest idea what the granularity of spacetime means, engaging with this book as an internally coherent work of philosophy and literature is rewarding enough. And Rovelli’s conclusion is powerful: we are physical systems dancing among other physical systems, and the world “is our blood brother”. We’re at home, among family. Perhaps it’s time we honoured that kinship.