Carlo Rovelli's On the Equality of All Things: A Physicist Turns Philosopher

Carlo Rovelli's latest book, On the Equality of All Things, sets out nothing less than a physicist's guide to life, the universe and everything — and it may be the most overtly philosophical work the Italian scientist has produced to date.

The signal of its sweeping ambition appears early, in an unusual place: the index. Under the letter "B" alone, readers find Francis Bacon, bats, behaviourism, Henri Bergson, and the big bang. That eclectic miscellany captures the range of a book that moves freely across the history of science, philosophy and the study of mind.

Rovelli directs a quantum gravity research group in Marseille. He has built his reputation as one of the most widely read popularisers of physics alive, with several books on the subject written for general audiences. The best known is Seven Brief Lessons on Physics, a global bestseller that established his signature blend of scientific explanation and lyrical compression.

His new book pushes that project further. Rather than simply explaining physics, Rovelli attempts to integrate principles and theories from the discipline into a broader Weltanschauung — a comprehensive worldview. Its central claims are two: the essential unity of all things, and the profoundly relational and perspectival nature of the universe.

The book's near-mystical musings reflect Rovelli's conviction that we stand on the brink of a revolution in understanding ourselves. The scientific and the philosophical are, in his account, not separate enterprises but mutually illuminating ones.

Rovelli states the stakes in his own words. "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."

That sentence carries the book's argument in miniature. Physics does not sit above other forms of knowledge, supplying final answers to questions that philosophy and the humanities pose. Instead, in Rovelli's framing, the categories of physics — electrons, stones, laws — and the categories of human understanding — minds, judgments — operate on the same ontological level.

The index entries under "B" make the genealogy of this position visible. Francis Bacon anchors the book in the scientific revolution. Henri Bergson connects it to a philosophical tradition that resisted reducing lived experience to mechanistic description. The big bang situates the whole inquiry within cosmology. Bats and behaviourism point toward questions of consciousness and perception that have haunted the borderlands between physics and philosophy for decades.

For readers who followed Rovelli from Seven Brief Lessons on Physics, the new book marks a clear development in his writing: from explanation toward argument, and from physics toward a metaphysics grounded in physics.

Whether the scientific establishment and philosophical readers will accept that a quantum gravity researcher has standing to construct a unified worldview is another question — one this book is certain to provoke.