I Am a Strange Loop

Back now to philosopher John Searle. He has gotten a lot of mileage out of the fact that a Turing machine is an abstract machine, and therefore could, in principle, be built out of any materials whatsoever. In a ploy that, in my opinion, should fool only third-graders but that unfortunately takes in great multitudes of his professional colleagues, he pokes merciless fun at the idea that thinking could ever be implemented in a system made of such far-fetched physical substrates as toilet paper and pebbles (the tape would be an infinite roll of toilet paper, and a pebble on a square of paper would act as the dot in a cell), or Tinkertoys, or a vast assemblage of beer cans and ping-pong balls bashing together.

In his vivid writings, Searle gives the appearance of tossing off these humorous images light-heartedly and spontaneously, but in fact he is carefully and premeditatedly instilling in his readers a profound prejudice, or perhaps merely profiting from a preexistent prejudice. After all, it does sound preposterous to propose “thinking toilet paper” (no matter how long the roll might be, and regardless of whether pebbles are thrown in for good measure), or “thinking beer cans”, “thinking Tinkertoys”, and so forth. The light-hearted, apparently spontaneous images that Searle puts up for mockery are in reality skillfully calculated to make his readers scoff at such notions without giving them further thought — and sadly, they often work.

The Terribly Thirsty Beer Can

Indeed, Searle goes very far in his attempt to ridicule the systems that he portrays in this humorous fashion. For example, to ridicule the notion that a gigantic system of interacting beer cans might “have experiences” (yet another term for consciousness), he takes thirst as the experience in question, and then, in what seems like a casual allusion to something obvious to everyone, he drops the idea that in such a system there would have to be one particular can that would “pop up” (whatever that might mean, since he conveniently leaves out all description of how these beer cans might interact) on which the English words “I am thirsty” are written. The popping-up of this single beer can (a micro-element of a vast system, and thus comparable to, say, one neuron or one synapse in a brain) is meant to constitute the system’s experience of thirst. In fact, Searle has chosen this silly image very deliberately, because he knows that no one would attribute it the slightest amount of plausibility. How could a metallic beer can possibly experience thirst? And how would its “popping up” constitute thirst? And why should the words “I am thirsty” written on a beer can be taken any more seriously than the words “I want to be washed” scribbled on a truck caked in mud?

The sad truth is that this image is the most ludicrous possible distortion of computer-based research aimed at understanding how cognition and sensation take place in minds. It could be criticized in any number of ways, but the key sleight of hand that I would like to focus on here is how Searle casually states that the experience claimed for this beer-can brain model is localized to one single beer can, and how he carefully avoids any suggestion that one might instead seek the system’s experience of thirst in a more complex, more global, high-level property of the beer cans’ configuration.

When one seriously tries to think of how a beer-can model of thinking or sensation might be implemented, the “thinking” and the “feeling”, no matter how superficial they might be, would not be localized phenomena associated with a single beer can. They would be vast processes involving millions or billions or trillions of beer cans, and the state of “experiencing thirst” would not reside in three English words pre-painted on the side of a single beer can that popped up, but in a very intricate pattern involving huge numbers of beer cans. In short, Searle is merely mocking a trivial target of his own invention. No serious modeler of mental processes would ever propose the idea of one lonely beer can (or neuron) for each sensation or concept, and so Searle’s cheap shot misses the mark by a wide margin.