In the spring of 1954, a housekeeper arrived at a modest home in Wilmslow, England, and found Alan Turing dead beside a half-eaten apple. He was 41 years old. The man who had helped break the Nazi Enigma code, who had conceived the theoretical blueprint for the modern computer, and who had asked—with breathtaking seriousness—whether machines might one day think, had been driven to ruin by the very government his genius had helped save. Convicted two years earlier of “gross indecency” for his relationship with another man, Turing had been subjected to chemical castration as an alternative to prison. The apple beside him was never tested for cyanide, and the coroner ruled it a suicide. Whether it was remains an open question. What is not in question is that one of the most consequential minds of the 20th century was silenced at the precise moment it had the most left to say.
Few thinkers have asked a simpler question with more staggering implications. When Alan Turing (1912–1954) posed “Can machines think?” in his landmark 1950 paper Computing Machinery and Intelligence, he wasn’t idly speculating. He was cracking open an entirely new frontier in philosophy, one that cut to the heart of what minds are, what intelligence means, and what separates human thought from mere calculation. His earlier conception of the “Turing machine” had already laid the theoretical groundwork for modern computing, but it was this later, more unsettling question that would echo across generations, growing louder with every passing decade rather than fading into academic history.
That echo is now deafening. In an era where artificial intelligence influences how we work, communicate, create, and govern ourselves, Turing’s challenge has evolved from a philosophical seminar to the center of civilizational debate. Questions about automation, consciousness, and the limits of human invention are no longer abstract. They are urgent, contested, and unresolved, which is precisely what makes returning to Turing so important. He did not give us answers so much as a way of asking, and in that sense, his work is less a historical artifact than a living provocation.
To explore that provocation, we turn to David Leavitt, Professor of English at the University of Florida and an acclaimed novelist, essayist, and biographer whose book The Man Who Knew Too Much: Alan Turing and the Origins of the Computer illuminates both the scientific brilliance and the human vulnerability at the core of Turing’s story. A recipient of fellowships from the National Endowment for the Arts and the Guggenheim Foundation, and named a Literary Lion by the New York Public Library, Leavitt brings scholarly rigor and a novelist’s deep empathy to the task. In this interview, he reflects on the man behind the machine, the philosophical stakes of Turing’s work, and why a question posed more than 70 years ago has never felt more alive.
Charles Carlini: You’re a critically acclaimed novelist and a professor of English at the University of Florida. What prompted you to write a book on an obscure mathematician by the name of Alan Turing, covering such arcane topics as Gödel’s Incompleteness Theorems, recursion theory, Church’s lambda calculus, etc.? Do you have a mathematical background?
David Leavitt: My mathematical education ended with high school calculus. Some twenty-five years later, James Atlas, esteemed biographer, editor, and founder of Atlas Books, wrote to tell me he was launching a series of short books on great scientific discoveries and to ask me if I might consider contributing a volume on Turing. At that time, I knew something about Turing’s life—in particular, the tragic circumstances of his last years—but virtually nothing about his work. When I agreed to do the book, I assumed that I would soft-pedal the math and focus on Turing’s biography. The more I read, however, the more the math fascinated me. I realized that to do Turing justice I would have to represent how his mind worked and to explore the connections between his forays into mathematical speculation and his strange personal journey.
CC: Alan Turing is widely regarded as the father of modern computer science. Can you summarize his contributions to this field?
DL. In his famous paper “On Computable Numbers,” Turing conceptualizes, for the first time, the idea of a machine capable of calculating any algorithm presented to it. Although the concept of a calculating machine or “difference engine” dates back to the nineteenth century, Turing was the first person to propose—and draw a plan for—a machine that was not task-specific but rather capable of transforming itself into any of an infinite number of task-specific machines: a universal machine. Such a machine, he theorized, would need to be simple in design. More importantly, the “instructions” by which it undertook a specific algorithm would have to be written in the same language as the algorithm itself. In proposing this radical idea, he in effect invented programming and the concept of software. Later in his career, Turing participated in the construction and programming of one of the first supercomputers, the Manchester “Baby.” His last and perhaps most significant contribution to the field was philosophical: in his famous paper “Computing Machinery and Intelligence,” he addressed the complex question of whether a machine could ever be said to think and proposed a test to determine the answer.
CC: As a consequence of his work in the advancement of modern computer science, his research overlapped with philosophy, anticipating the concept of artificial intelligence. Can you tell us what his views were on this?
DL: Turing's argument for computer intelligence rests on the premise that behavior equals identity. If a machine persuades you that it is thinking, then it is thinking. How we behave is who we are. Critics countered that thought necessitated consciousness: to think, a mind or a machine has to be able to know itself to be thinking.
In "Computing Machinery and Intelligence," Turing anticipates not only a future in which thinking machines exist but the likelihood that they in that future will be the victims of discrimination. Fearful of the machines, humans "born in the usual manner" will oppress them. In this regard, his polemic reflects his own experience as a gay man living in a country that criminalized homosexuality. His cry for "fair play for the machines" encodes a cry for an end to discrimination.
Alan Turing finishing a race in 1946CC: Can you explain Turing’s hypothetical test for whether a computer could think, the so-called Turing Test?
DL: An extremely abbreviated gloss:
C is told that A and B are a man and a woman, but not which is the man and which is the woman. C must assign a gender to each purely on the basis of typewritten answers. A and B do everything they can not just to influence C but to suggest that the other is lying. Now, let us suppose that A and B are a human being and a machine. C must likewise determine which is which. If the machine persuades C that it can think—that it is human—then it has passed the test. This constitutes, in Turing’s mind, proof that machines can think.
CC: At Cambridge University, Turing attended lectures by philosopher Ludwig Wittgenstein on the Foundations of Mathematics. The two were said to have argued over certain fundamental issues. Can you tell us more about this?
DL: In his famous seminar on the foundations of mathematics, Wittgenstein cast Turing, rather against his will, in the role of the “mathematician.” Their arguments were fruitful and stimulating, but, as is usually the case with philosophy, generated more questions than answers.
CC: It has been said that Turing’s work on deciphering the German Enigma code at Bletchley Park during the Second World War made a significant contribution to winning that war. How so?
DL: As the architect of the "Bombe"—a machine specifically designed to break a code generated by another machine (the German Enigma)—Turing laid the foundations for a massive code-breaking operation as a result of which the Allies were able to gain a significant advantage over the Germans in that portion of the war that took place in the waters of the Atlantic.
CC: From 1936 to 1938, Turing studied at the Institute for Advanced Studies in Princeton, where Kurt Gödel lectured. Did they cross paths at any point?
DL: Only briefly. Turing was very shy, and Gödel, at this point, reclusive.
CC: How was Turing’s own work related to Kurt Gödel's Incompleteness Theorem?
DL: David Hilbert called for proofs of the completeness, consistency, and decidability of a mathematical system such as the one put forth by Russell and Whitehead in their tome Principia Mathematica. Godel proved that such a system could be neither complete nor consistent, Turing that it could not be decidable.
CC: During his final years, Turing became interested in chemistry. Can you describe his work in this area?
DL: This is the aspect of Turing’s life about which I know the very least.
CC: Turing ended his life after eating a cyanide-laced apple. His death was ruled a suicide, though rumors of assassination still linger. What is your take on this?
DL: So long as the documents and files relating to Turing’s death remain classified, this is an open question.
Photo Credit: Anthony Rue
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