Long, long ago, before machines could speak, and far before anyone even dreamt of them being able to write poetry, beat the chess world champions or finish your sentences, one man thought they would someday do so. While the world was still dreaming that computers were proof-of-concept glorified calculators, John McCarthy was imagining something far bolder: machines that thought. He created the term artificial intelligence before most of us had ever really imagined what that meant. And yet, even being a cornerstone architect of this cognitive revolution, McCarthy remains a quiet legend — more history than headline, more source code than story.
The Word that Started It All
At a summer workshop at Dartmouth College in 1956, McCarthy introduced a term that would help shape the arc of modern science: Artificial Intelligence. He brought together a ragtag group of mathematicians, engineers, and logicians for a speculative endeavor to model human reasoning. The gambit was audacious. “Every aspect of learning or any other feature of intelligence can in principle be so precisely described that a machine can be made to simulate it.”
That phrase triggered a sequence. It became a kind of command line invocation that booted up one of the most consequential research programs in human history.
But McCarthy was no utopian idealist. He certainly didn’t expect sentient androids overnight. He was a logician first, a mathematician second, and a pragmatist. His ideas for AI were embedded in layers of recursion, complexity, and formalism, not science fiction drama.
LISP: A Language for the Mind
If McCarthy’s original formulation of “AI” was his conceptual lightbulb, then the elaboration of LISP in 1958 was his engineering tool. LISP, now the second oldest programming language actively used today, was not simply a tool, but a reflection of his belief that programs could manipulate symbols and data simultaneously and that manipulation was always more significant than mere calculation. LISP – unlike FORTRAN, which was about numbers – was about ideas.
LISP’s recursive structure mimicked human reasoning. LISP could write code that wrote other code. LISP also introduced ideas that would become staples of modern computing, such as garbage collection, tree data structures, and dynamic typing.
Overall, McCarthy’s LISP created an enduring, not just useful, programming language and epistemological playground for reflection on syntax.
Philosopher in a Lab Coat
John McCarthy was not motivated by the riches or applause. He was motivated by puzzles. He viewed computers not as tools for computation but as machines that would reflect the mind. He argued vigorously against the claim that machines are simply not intelligent beings. His opinion was unequivocal: intelligence is not an intrinsic property of human beings—it is a property of behavior. If a machine behaves intelligently, then it is intelligent by definition.
He was oppositional on aspects of anthropomorphic anxiety: the fear that if I give intelligence to a machine, I somehow diminish the uniqueness of humans. To McCarthy, this concern is laughable. Tools do not have to be human to be useful. They simply need to work.
However, while he was open to philosophy, he was also a realist. He had rejected neural networks from the start — he distrusted their probabilistic nature and transparency issues. He believed in logic and formal proofs. Some of the very probabilistic AI developments during the 2010s — deep learning, black-box models—were maybe the reverse of his implicit symbolic ideal.
Cold Wars and Hot Minds
McCarthy’s work did not happen in a vacuum. The middle of the 20th century was a time of significant scientific and military strife. Governments were seeing AI as a strategic necessity. Defense funding poured into AI labs—McCarthy’s own Stanford AI Lab (SAIL) had opened back in the early 1960s, where he oversaw generations of future greats, from John McCarthy, his mind imparted to theirs in one manner or another.
He designed early time-sharing computer systems because he thought people should share computing power and be empowered to do so. In a sense, he was doing something like democratizing computer access and power — half a century in advance. He designed a utility computing service, which we now call cloud computing, back in 1961 itself.
He was always a couple of decades early.
A Voice In The Wilderness
McCarthy was an academically gifted man. He was disconnected from the glamour of Silicon Valley startups and initial public offerings, and he wasn’t a billionaire. He did not start companies. He stayed rooted in his laboratory, developing ideas. As machine learning emerged as the dominant trend and fashion, the logic-first stance espoused by McCarthy was quickly disregarded. He was unperturbed.
He was a believer in reason. And he believed that reason could be mechanized.
Some people worried about the risk of misbehaving, runaway AI, while McCarthy dismissed their anxiety. “If robots are capable of making mistakes, then so are humans,” he would say to his peers. Intelligence, whether human or otherwise, was a tool, not a moral actor. It was a decision for society to make.
A Quiet Departure
John McCarthy passed away in 2011, and it was also the year the modern resurrection of AI began. Siri was launched that year. Deep learning was being reinvigorated. The AI arms race between companies was starting to intensify. The world he imagined was beginning to materialize.
He did not live to experience ChatGPT or AlphaGo. But he is still, in a very real sense, everywhere.
From logic-based AI to the notion that intelligence is system output and not the system’s soul, McCarthy’s ideas are the substrate of almost every serious discussion on what it means to “think.” The most advanced language models today are trained on probability, but they are underpinned with languages, abstractions, and design patterns that LISP and McCarthy helped to create.
Legacy: The Invisible Father
If Alan Turing provided us with the question, “Can machines think?” — then John McCarthy provided us with the toolbox to answer it.
He didn’t care about celebrity status. He wasn’t plaguily committed to justifying himself. He hadn’t set out to create a legend. Still, in his reserve, he turned into a legend. The mind of AI, who never called himself that.
In a world high on spectacle, John McCarthy was the ascetic. In the age of machine learning giants, he has become a spectre in footnotes and function calls. But make no mistake: the era of intelligent machines, with all its complexity and contradiction, stands on his shoulders.
Ultimately, McCarthy’s most radical act was not to invent a name or language- it was to imagine intelligence was not divine, was not singular, something we could build.
He did not just invent artificial intelligence.
He opened our eyes that intelligence, itself, might be artificial.