Book Review: "Flesh and Machines" by Rodney A. Brooks
"The distinction between us and robots is going to disappear." This is Dr. Rodney A. Brooks' closing message in Flesh and Machines. According to Brooks, humans — viewed from a certain perspective — are already machines: our bodies operate according to physical laws, biological constraints, and internal rules that govern perception and action. This is a position I largely agree with. Yet what makes Brooks’ argument compelling is that, despite describing humans in mechanistic terms, he never reduces them to mere machines. On the contrary, he treats human experience — emotion, empathy, and social meaning — as central. The result is not a "flattening" of humanity, but a reframing of it: humans and machines as fundamentally similar in kind, yet different in form, history, and relationship.
Before arriving at this philosophical conclusion, Brooks carefully maps out both the history of robotics and his own personal journey through it. He begins with the agricultural age, emphasizing machines that were purely mechanical and task-driven, and gradually traces the evolution toward more adaptive and interactive systems. From there, he transitions into discussions of Artificial Intelligence (AI), famously invoking HAL 9000 from 2001: A Space Odyssey as a cultural symbol of our hopes and anxieties about thinking machines. This leads naturally into artificial life (ALife) and the idea that intelligence does not emerge from abstract reasoning alone, but from physical bodies acting in the world. Brooks then grounds these ideas in everyday reality: cleaning robots in our homes, wearable devices on our bodies, and prosthetics that blur the line between organism and machine. Only after laying this foundation does he turn inward, asking how these machines force us to rethink what it means to be human.
Of all the themes in the book, I found Brooks’ later discussion — on treating ourselves as machines — to be the most provocative. If humans are systems whose bodies follow rules, and robots are systems whose bodies follow programs, then the difference between the two becomes one of degree rather than essence. This raises an uncomfortable but fascinating question: if we grant humans moral "specialness" despite our mechanistic nature, could we someday extend a similar kind of consideration to robots? Brooks does not argue that robots deserve empathy in the same way humans do, but he challenges the intuition that such empathy is categorically impossible. This line of thought unsettles long-held assumptions about consciousness, agency, and dignity.
Not everyone is willing to accept this erosion of human exceptionalism. The physicist Roger Penrose, for instance, has famously argued against the possibility of true AI, claiming that human consciousness cannot be reduced to mere algorithms and may instead arise from as-yet-unproven quantum effects in the brain. Brooks acknowledges that Penrose might be correct, but he pushes back on the speculative nature of this argument. Penrose appeals to "new stuff" in physics that has not been empirically demonstrated, while Brooks insists that we should work with what we know rather than what we hope will preserve human uniqueness. More pointedly, Brooks suggests that such resistance may be emotionally motivated — that the discomfort lies not in the science, but in the reluctance to relinquish the idea that humans occupy a privileged position in the universe.
In the end, Flesh and Machines is less a technical manifesto than a philosophical meditation grounded in decades of engineering practice. Brooks does not claim that humans and machines are already the same, but he argues persuasively that the boundary between them is neither fixed nor sacred. I find myself agreeing with his closing message. As machines become increasingly embodied and integrated into our lives, the distinction between flesh and machine may not disappear all at once — but it may slowly lose its meaning. ###