McCulloch
What I am trying to do as a scientist is a very simple and clear-cut story. It begins back about 1917. I was at about nineteen years old. I had been brought up with every expectation of going into the Christian ministry—which in my family means the Episcopal Church. I was soaked in theology.
Narrator
This is Dr. Warren McCullouch, an eminent neurologist, engineer, and mathematician. It was at his world-famous lab at MIT that the original work on the frog’s eye took place.
McCulloch
And I got seduced by mathematics surely because there was more fun in it, and because—if you know theology at all well—you will realize that the ideas in the mind of God are mathematics and logic. So this is the way I came into the game in the first place.
And I have never had but one question in the whole of my scientific life. I’ve only wanted to know: what is a number that a man may know it, and a man that he may know a number? I think I’m fairly clear as to the first half of it, but as the second half—a man that he may know a number—nu-uh. Not yet. I’ve had to content myself with what a frog’s eye tells a frog’s brain, or something else of this sort. So roughly—
Narrator
A frog’s eye is very simple compared to a man’s brain, an organ so complex that even the most optimistic believe that it will be centuries before we unravel all its mysteries. Yet, Dr. McCullouch and his colleagues believe they are beginning to understand how the higher nervous system, a man’s brain, might work as a machine—a machine basically different in principle from anything we can now build; much more subtle than even our most sophisticated computers.
McCulloch
Now, may I make clear a distinction between your nervous system and any computing machine which is yet in existence? There are some beginning to approximate it. They are to be found chiefly in bombers and things of this sort. Now, in an ordinary machine, operations are carried out sequentially. And a mistake entails mistakes which follow inevitably from it all the way through the computation. As opposed to this, there are parallel machines—that is, machines which carry on the same computation in one, two, three, or more channels. Compare the results and don’t go ahead until the results agree. These are strictly parallel.
I’m not talking about either of these kinds of machines. I’m talking about machines which resemble, let’s say, the mouth of the Danube or the mouth of the Nile—or better yet, the mouth of the Suwannee River. These are what the Greeks called anastomotic affairs. That is: the water from each contributory stream is mixed with the water from every other contributory stream before they finally get out the mouths of the river. Is that clear? There is no other word that I know for it except the old Greek word anastomotic. They’re not merely braided together, where the braids follow through. No, no. They’re braided with an intermixture so that the information coming out at any one point in the mouth is combined from the information coming in from all of the sources of that river. Is this clear? Good.
What is more—well, any man my age knows this very well. Neurons die at the order of thousands of neurons per day. We’re built to run well to the sixteenth year of age, roughly. From that time on you begin to be able to count the holes where there were cells and there are no more. So you have to design it so that a cell, while it’s dying—and while it’s dying, it’s have to go pip, pip, pip, pip, pip, brrrrepp, and then quit. And after it’s dead, it’s not going to make too much difference. You would probably find at least ten percent of the big cells in my cerebellum (where you could count them) are just holes filled up with glia, new cells, supporting cells. So this kind of thing happens all the time and must happen. And yet we can go on to—well, in my family—to a hundred.
Interviewer
And the theory that you’re working on explains—
McCulloch
The theory that we’re working on takes care of all of these things. That’s the important point about it.
Narrator
In the summer, Dr. McCullouch, his wife, and grandchildren moved to a country home in New England. All that was missing in this peaceful spot was a lake. And thirty years ago, McCullouch dammed up a stream to complete his Eden.
What is man? A child of nature—but now, wondering whether he can ever learn enough to make something like himself in a laboratory. What is the limit of our possible knowledge and power? Will we, one day in the distant future, perhaps even create beings superior to ourselves? Beings who will survive us on this planet? Dr. McCullouch thinks it’s possible.
McCulloch
No, I would expect that, insofar as machines might survive man—and they might—they would only carry on (in a sense) the same general direction that man would have carried on if he could have. Am I clear? So to speak, the machines would be standing on our shoulders.
Interviewer
Somehow, the purpose of it, that a machine—no matter how complicated and how clever—could have, to my mind, isn’t equatable. When man has gone, these machines would, in essence, be purposeless.
McCulloch
I doubt that. I would say, in essence, they would be purposeful.
Interviewer
And there would be, in your feeling, nothing gone and nothing missing from the world?
McCulloch
Well, you mean in the sense in which the dinosaurs are missing?
Interviewer
No, I mean in the sense of something important.
McCulloch
Well, aren’t they important? Weren’t they important? I mean, there’s one thing you can be pretty sure of: man won’t survive forever. From all that we know of the sun and of other stars, that would be the most improbable thing. Something else will come.
Interviewer
And in your opinion, it might be something of man’s own creation?
McCulloch
Yes.
Interviewer
Well, here’s the problem that I’m trying to get at. Here’s the thing that I’m trying to get at. You have two grandchildren right there. And I can’t see that a machine will ever feel toward any of its—
McCulloch
Why not?
Interviewer
—creatures the way you feel about them. That’s the one thing that I can’t get.
McCulloch
Well, I think I could set it up for you, because I’m certain that if I do it, there is a mechanism that can do it. If I can manage to state that in a finite and unambiguous manner, then I think it can be done. And I see no reason why we can’t develop a logic of relations in time to come. Granted, it’s defective at the present time.