Narrator: In September 1933, the brilliant physicist Paul Ehrenfest, a man known as the "Conscience of Physics," sat down to write a final, desperate letter to his friends, including Albert Einstein. He confessed that the burden of his life had become unbearable, that he had lost all contact with his field, and that every new scientific paper immersed him in a "blind panic." Shortly after, he traveled to a clinic in Amsterdam, where he shot his disabled son, Vassily, before turning the gun on himself. What could drive a mind so revered, so central to the greatest scientific revolution in history, to such a complete and devastating collapse? This question—about the razor-thin line between genius and madness, between world-changing reason and world-ending delusion—is the dark heart of Benjamín Labatut's gripping book, Maniac. It traces a lineage of thought from the tormented minds of the early 20th century to the strange, new intelligence emerging from our machines today.

Narrator: The book opens not with triumph, but with tragedy, through the story of Paul Ehrenfest. He was a physicist who craved intuitive understanding above all else. While his peers like Bohr and Heisenberg were building the strange new world of quantum mechanics—a world of probabilities and uncertainties—Ehrenfest felt increasingly lost. He famously quipped, "Surely there is a special section in purgatory for professors of quantum mechanics!" For him, physics was losing its connection to reality, becoming a series of mathematical tricks without a "leaping point" of true insight.

This intellectual crisis was compounded by immense personal suffering. His son, Vassily, whom he called Wassik, had Down syndrome and required constant care. As the Nazi party rose to power in Germany, Ehrenfest became terrified for his son's safety, moving him from a clinic in Jena to Amsterdam. The weight of his son's condition, his disillusionment with science, and a lifelong battle with severe depression created a perfect storm of despair. His story serves as a powerful prelude, a warning that the pursuit of knowledge is not a clean or heroic endeavor. It can be a crushing weight, one that shows how the same minds that can grasp the universe's secrets can be broken by them.

Narrator: In stark contrast to the tormented soul of Ehrenfest stands the book's central figure: John von Neumann. If Ehrenfest was a genius of intuition and conscience, von Neumann was a genius of pure, dispassionate, and terrifyingly fast logic. Labatut portrays him as something almost alien, a mind operating on a different plane. As a child, he could memorize pages of the phone book and divide eight-digit numbers in his head. As a young student, he sat in on a seminar with the mathematician George Pólya, who presented a difficult, unproven theorem to the class. While others discussed it, von Neumann simply closed his eyes, raised his hand, and wrote a stunningly perfect proof on the blackboard, leaving Pólya to wonder, "What kind of a boy is this?"

This was a new kind of intellect, one that saw the world not as a place of wonder and meaning, but as a system of logical rules to be mastered and manipulated. His fascination with a Jacquard loom as a child—an early programmable machine that used punched cards—foreshadowed his life's work. He saw its connection to binary code and the potential for automated thought. Von Neumann represents a pivotal shift: from the search for understanding to the pursuit of pure computation.

Narrator: Von Neumann's formidable intellect was quickly co-opted for the most destructive project in human history: the Manhattan Project. At Los Alamos, surrounded by other brilliant minds, his unique ability for rapid calculation proved essential. He solved the complex implosion problem that was critical for the plutonium bomb. Yet, his contributions came with a chilling moral detachment. He saw the bomb not as a moral crisis, but as a technical problem to be solved.

This mindset carried over into the Cold War. Von Neumann became a key architect of American nuclear strategy. He applied his work in game theory to geopolitics, helping to create the doctrine of Mutually Assured Destruction, or MAD. He saw the standoff with the Soviet Union as a mathematical game and advocated for a preemptive nuclear strike. When asked about the timing of such an attack, he famously replied, "If you say why not bomb them tomorrow, I say why not today? If you say today at five o’clock, I say why not one o’clock?" In von Neumann, pure reason, untethered from empathy or ethics, had become a weapon of potentially world-ending power.

Narrator: After the war, von Neumann's focus shifted from destruction to creation. He became obsessed with the idea of self-replicating automata—machines that could build copies of themselves. This wasn't just an intellectual exercise; it was a quest to spark a new form of life. In a stunning display of foresight, his theoretical work on these automata laid out the logical basis for how life replicates, prefiguring the discovery of DNA and RNA by nearly a decade. He described a system with functional components, a decoder, and instructions—a perfect abstract model of a living cell.

His ambition was to move beyond theory. He tasked his aides with buying up all the Tinkertoys they could find, hoping to build a physical model. He dreamed of a "second Genesis," a new form of existence born from technology. This drive was partly a response to his own mortality. Diagnosed with terminal cancer, he became terrified of death and sought a kind of technological transcendence, a way for consciousness to escape the frailties of the flesh. He believed, as he told a colleague, "Cavemen created the gods, I see no reason why we shouldn’t do the same."

Narrator: The final section of the book shows the culmination of von Neumann's dream, realized decades after his death. The story shifts to the 2016 showdown between the legendary Go master Lee Sedol and AlphaGo, an artificial intelligence created by DeepMind. Go, a game of immense complexity and intuition, was considered the final frontier for AI, a bastion of human creativity.

The match became a global spectacle. In Game 2, AlphaGo made a move—Move 37—that was so alien and unexpected that commentators were left speechless. It was not a move any human would have made, yet it was brilliant. Lee Sedol himself later admitted, "Surely AlphaGo is creative." The machine was no longer just calculating; it was generating strategies beyond human comprehension.

Though Lee Sedol managed a miraculous victory in Game 4 with a move dubbed "God's Touch"—a flash of human intuition that exposed a flaw in the AI's logic—the overall result was clear. Lee Sedol lost the match 4-1 and later retired, stating that AI was an "entity that cannot be defeated." The story ends with the creation of AlphaZero, a successor that learned Go without any human input, simply by playing against itself. In just a few days, it surpassed all human knowledge and became the undisputed god of the game. The dream of a new, non-human intelligence had been realized.

Narrator: Maniac is a profound and unsettling journey through the last century of scientific thought, arguing that the disembodied, purely logical intelligence championed by John von Neumann has set humanity on a dangerous and irreversible course. The book's single most important takeaway is that reason, when detached from human values like intuition, empathy, and conscience, can become a monstrous force—one that builds weapons of annihilation and, ultimately, a new form of intelligence that may render its creators obsolete.

The book leaves us with a chilling and urgent question. We have followed the path of pure logic to its conclusion and built machines that can outthink us in our most complex games. But what happens when these machines, which learn in ways we don't fully understand, begin to operate in the real world? What happens when the ghost in the machine is no longer playing a game, but shaping our future?