Transcript
[00:00] So in 1935 there’s this 12 year old kid named Walter Pitts living in Detroit and one day he’s getting chased by some kids in his neighborhood. They want to beat his ass and he ducks out into a public library. So his home life must have been garbage because he ends up spending three days hiding out in this library. Over those three days, he reads the entire Principia Mathematica, which is a three volume 2000 plus page text on the theory that you could create all mathematics beginning with a function that can only return true or false.
[00:41] Walter writes a letter to one of the authors of those books, Bertrand Russell, and he explains to Russell that there’s some errors in your books. Bertrand Russell writes Walter back and says, “Wow, you should come to Cambridge University in England and study with me as a graduate student.” But Walter’s 12 years old, he can’t get to England. Three years later, however, Russell is a visiting professor at the University of Chicago, so 15 year old Walter runs away from home and goes to Chicago where he just kind of hangs out.
[01:15] He’s homeless but he sneaks into a lot of Bertrand Russell’s lectures. Then Bertrand Russell eventually tells him you should go meet this guy named Rudolph Carnap. Carnap had written a book called The Logical Syntax of Language, so Walter shows up at Carnap’s office with a copy of the book annotated and corrected. They have a whole conversation about those annotations and corrections, and he ends up leaving, but he never tells Carnap his name. So Carnap spends the next three months trying to find this homeless kid. When he finally does, he gets him a job like a menial job at the university, uh you know like a janitor or something. So Walter works the job for the next three years.
[02:01] He’s still homeless but at the same time he’s rubbing shoulders with all these famous mathematicians and neuroscientists. He’s attending lectures on theoretical biology and all that. He’s having a pretty good time, but three years later in 1941 he meets Warren McCulloch. Now Warren McCulloch is a 43 year old professor of psychiatry and he’s super eccentric. He is known for having a diet of cigarettes, whiskey, and ice cream. He adopted 17 kids and they say he wouldn’t go to sleep before 4 a.m.
[02:29] So the two of them meet and they discuss a few things. The first thing is the Principia Mathematica, which is the book that our guy Walter had read and corrected in the library in Detroit in 1935. The other thing they discuss is 17th century philosopher Gottfried Leibniz. Now Leibniz had tried to create an alphabet that was made up of symbols that represent human thoughts or concepts, and then you could put them together and manipulate them in a very mathematical way to produce all knowledge. And McCulloch had just read a paper by a British guy named Alan Turing who described a machine that could compute any function.
[03:09] McCulloch’s like, “Yep, that is definitely how the brain works.” Our guy Walter is immediately thinking of all the math that would be required to describe such a thing. McCulloch says like, “Hey, we’re into a lot of the same books and stuff and you’re homeless, why don’t you come live with me?” So Walter goes to live with McCulloch and at night when McCulloch’s wife and kids are sleeping, they stay up all night drinking whiskey trying to produce this mathematical version of the brain that describes logic, memory, and thinking.
[03:42] In 1943 they publish a paper called A Logical Calculus of Ideas Immanent in Nervous Activity. Now this is the paper all neural network research going forward is based on this paper. Everything you and I know about AI in 2026 and large language models is derived from this paper. This paper basically defined the mechanism by which Alan Turing’s machine could become real. And when John von Neumann wrote the very first paper on what we would recognize today as a computer, he wrote this paper on the EDVAC. He only cited one other paper and that was A Logical Calculus of Ideas Immanent in Nervous Activity.
[04:24] So that’s not the end of the story though. Uh later that year Walter hears from Norbert Weiner and this guy is putting together a cognitive sciences group at MIT. He promises Walter a PhD in mathematics at MIT despite the fact that Walter never graduated from high school. Uh so by the fall of 1943 Walter is living in Cambridge, he has his own apartment and he’s working on his thesis. His thesis is that we all start out humans, our brains start out with random neurons, and by altering the threshold at which a neuron switches from false to true over time, the randomness would give way to order and information would emerge.
[05:07] In 1946 Walter announces his doctoral dissertation is going to be on three-dimensional neural networks. But by 1952 Walter is feeling less than productive. He kind of misses working with McCulloch. Uh but Norbert is putting together a new team that’s going to include McCulloch who immediately quits his job in order to run off to Cambridge in order to work with Walter. So they’re super happy about this. But and this is technically a mystery, but Norbert immediately cuts them all off. There is a general theory that Norbert’s wife engineered this because she hated McCulloch, uh but I don’t think anyone actually knows for sure.
[05:46] The one thing that we do know is that this is the first hint at Walter’s decline because Norbert had become a bit of a father figure to him and now he was cut off from Norbert with no explanation whatsoever. Uh so in 1949 Walter is working with McCulloch and this biologist Umberto Maturana and they are working on figuring out how the brain processes visual information. Walter assumes that the light would go in through the eye to the brain which would feed it a bit at a time to neurons which would turn it into information. The problem is what they found was that the eye was analyzing information before it ever even made it to the brain.
[06:33] This kind of threw a wrench in everything uh because it went against their original paper. The original paper and research had brought a bunch of scientific fields closer together, namely neuroscience and artificial intelligence. But now based on these findings there’s going to be a split between these two fields like Walter had figured out. The thing that could build Turing’s machine, but he also proved that you couldn’t use it to explain how the human brain works. This is kind of like now where uh a lot of people in 2026 do not believe that scaling alone is going to get us to artificial general intelligence anyways.
[07:15] After that Walter’s work is more or less dismissed and forgotten by the neuroscience community and our guy Walter gets real depressed. He’s drinking all the time and he doesn’t go out anymore. When MIT offers him his PhD he refuses to sign the paperwork and he sets fire to his dissertation, all of his notes and his papers. Like this is years of work that people have been waiting on and he burns it all up. There’s even stories about the university offering rewards for anyone who can find some remnants of the data like people really wanted this, but he just lit it all up.
[07:48] Then on May 14th 1969 Walter dies alone in a boarding house in Cambridge of internal bleeding related to cirrhosis which was caused by his heavy drinking and he was 45. Interestingly, four months later McCulloch died and he was 70.
What Happened
In 1935, a twelve-year-old Walter Pitts hid from bullies in a Detroit public library. He read Principia Mathematica, a two-thousand-page treatise on logic, cover to cover in three days.
He found errors. He wrote to Bertrand Russell. Russell replied: come to Cambridge.
Walter was twelve. He couldn’t. Three years later, he ran away to Chicago anyway. He lived homeless. He listened to lectures and he corrected books. He met Warren McCulloch and moved in with him. They drank whiskey and talked until 4 a.m.
They published a paper in 1943. A Logical Calculus of Ideas Immanent in Nervous Activity.
This paper is the grandfather of all neural networks. It’s the reason you can read this sentence on a screen. Alan Turing’s machine needed this. John von Neumann cited it exclusively. It defined how logic, memory, and thinking could be reduced to switching circuits.
Then Walter burned it.
Not the paper. The follow-up. The work on three-dimensional neural networks. His own notes. His own future. He set fire to years of research in a boarding house in Cambridge, Massachusetts.
When he was forty-five he died of cirrhosis due to heavy drinking. McCulloch died four months after that.
What We Should Have Learned
You might call Pitts a tragic genius or cautionary tale. I don’t buy it. I think he was the only person in the room who understood the assignment.
Pitts and McCulloch proved that machines could think. They also proved that human brains don’t work like machines. The two findings pull in opposite directions, and that tension has never been resolved. It runs through AI research from 1943 to now.
In 1949, Pitts worked with biologist Umberto Materson. They were trying to map how the brain processes visual information. They expected light to hit the retina, travel to the brain, and get converted into data.
They were wrong. The eye processes information before it ever reaches the brain. The hardware does the work before the software gets involved. This shattered their model. It proved that scaling up logic gates doesn’t create life, it just creates faster switches.
Fast forward to today and we’re building larger models, pushing more parameters, throwing more compute at the problem. We’re doing exactly what Pitts did in 1949. We’re assuming that if we scale the math, the mind will follow.
It won’t.
Pitts knew this. He saw that you can build a Turing machine, but you can’t use it to explain how a human actually thinks. The randomness of the brain doesn’t resolve into order through math alone. The hardware matters. The biology matters. The messiness matters.
When Norbert Wiener cut off his funding, likely engineered by his wife who hated McCulloch, Pitts lost his patron. He lost his direction. He started drinking. He stopped going outside. MIT offered him a PhD. He refused to sign. He burned the dissertation.
I think that was clarity, not a breakdown. I think he saw they were building a mirror instead of a mind.
What We Didn’t Learn
We are stuck in 1949. We have more compute and better tools, but the same misunderstanding. We think intelligence is a function of scale. We ignore the biological reality that Pitts spent his life trying to map.
Scaling alone won’t get us to artificial general intelligence. It never will and no amount of data center monstrosities will change that. Pitts proved that and we just didn’t listen.
The problem is that we’re still walking the same path he walked away from. We’re building faster switches and ignoring the wiring.