Philip Ball is a veteran science writer whose books have shed light on a wide range of subjects, including molecular physics, pattern formation, music psychology, and quantum physics. In The Book of Minds, Ball attempts to penetrate the mystery of “mindedness”.

How would it feel to experience the world like a bat or a bee? Can we create artificial minds? And if alien life forms are out there, how would their minds relate to ours?

Imagination and its limits

Ball introduces the idea of a “space of possible minds” in which to situate any being. Using dimensions such as consciousness, agency, intelligence, and experience, it becomes possible to at least speculate systematically about how an animal mind might differ from our own.

Ball then surveys the forms of thinking, sensing and reacting that can be found in living things. He provides a brief introduction to newer theories of consciousness like Integrated Information Theory, and summarizes the state of artificial intelligence around the time the book was written.

The author frequently reminds us that, while we can speculate about dimensions of “mindspace”, we cannot transcend the limitations of our own minds when imagining the experience of other beings.

That doesn’t stop him from speculating about the possible minds of extraterrestrials. Ball notes that much of our science fiction merely extends human qualities and motivations into “alien” minds—the war-like species, the scientific species, etc. He reaches the obvious conclusion that we can say very little about what alien minds would actually be like.

Why agency matters

In the penultimate chapter, Ball engages in an impassioned defense of the concept of “free will”. While acknowledging that the term is problematic due to metaphysical connotations and lack of clear definition, he argues that the concept of agency as realized through minds is crucial to make sense of the world.

Ball dismisses questions of determinism as irrelevant. Of course, he says, everything happens because it could not be otherwise—that’s a banal, even tautological observation. But the causes of events don’t become more intelligible by reducing a person’s decisions to the interaction between molecules in their brains.

Minds produce decisions—that’s what they evolved to do—and thereby they cause things to happen. That distinguishes minds from other objects in the universe. We therefore need to approach agency as a subject of study: Why and how do minds decide certain things? It’s an implicit defense of fields like psychology for comprehending a universe that has minds in it.

While the chapter is essentially a long philosophical argument, I found it to be the most interesting one in the book. As for the remainder of The Book of Minds, regular readers of science writing are unlikely to encounter a lot of ideas they’ve never heard of before.

The Verdict

Ultimately, Ball’s core subject is riddled with so much uncertainty that it does not really warrant a 500-page book. Readers have to work through a lot of variations of “we don’t know” or “we can’t know” to get to the ideas Ball wants to bring across. That’s a shame, because those ideas are interesting—they’re just buried in prose.