There's logic gates in me plumbing!

Contemplate this post. Here is a key passage from Shannon's original paper:

The method of attack on these problems may be described briefly as follows: any circuit is represented by a set of equations, the terms of the equations corresponding to the various relays and switches in the circuit. A calculus is developed for manipulating these equations by simple mathematical processes, most of which are similar to ordinary algebraic algorisms. This calculus is shown to be exactly analogous to the calculus of propositions used in the symbolic study of logic.

What I want to highlight here is that Shannon was talking about existing circuitry. Was this existing circuitry really doing symbolic logic all along? Or did Shannon just realize that we could interpret that circuitry as performing logical operations?

And there is no reason the "circuits" in question need be electrical: they can be plumbing, and what flows through them can be water. (Interestingly, the person who built this water computer had the goal of "demystifing the computer." And take a look at the photos of the logic gates in the link above.)

It is important to realize that every single thing the most sophisticated computer can calculate can, in principle, be calculated by a properly designed computer employing these "water gates." (The results will come out very slowly, but that has nothing to do with the logical possibility.) That is because both are theoretically equivalent to a Universal Turing Machine.

So if you watched the water flowing through a water computer, calculating, say, a chess move, would you be willing to say that this combination of water and pipes is "thinking about a chess move"? Or is it more plausible to say that the water is just flowing through the pipes as fluid mechanics dictates it will, and it is the cunning of the person who designed the pipes to realize that we humans can interpret what occurs as "calculating a chess move"?

Let us imagine that we happen upon a complex plumbing arrangement in an existing building, and we realize that, while the design was devised only to regulate water flow out of the building to meet certain municipal requirements, the system of valves also can be understood as implementing logic gates. We study the system, and determine that we can coordinate a series of toilet flushes and hand washing so as to perform arithmetic operations, and "read" the answer to a calculation by monitoring the water temperature and pressure in the outflow pipes. Does this mean that the building had been merrily doing arithmetic all along, unbeknownst to all its occupants and anyone else? Or have we just figured out a clever way of interpreting the building's plumbing system as performing arithmetic?

An analogy: one "deli" in my neighborhood, which is actually a numbers operation, uses the least significant digit of an agreed upon series of figures in the newspaper to "pick" the winning number each week. So, for instance, they can point customers at the AL batting average leaders table in the NY Post, and tell them, "The winning number is the last digit of the top eight hitters' averages, taken in sequence." (This works because the last digit is pretty random: the first digit will almost always be '3', and the second one typically less than '5', but the last will be distributed pretty randomly from '0' through '9'.) So has the NY Post always been picking winning numbers all along, or was it only the cleverness of the people running the game to realize it could be interpreted as doing so?

For a materialist who wants to assert that Big Blue really does think about chess, a way out of this difficulty, which does not involve asserting that thermostats think about their home's temperature, is to argue that in various situations, a certain amassing of quantity actually leads to a change in quality: it takes a large quantity of circuits, working at some minimum speed, to actually constitute thought. (This was Marx and Engels' solution to this sort of problem.*) But whether this is still materialism is doubtful: it actually seems to lead to panpsychism or hylomorphism, since whatever new qualities emerge are not simply "matter and energy in motion," but something non-material, irreducible to the merely material. And thus this route is firmly rejected by hardcore materialists such as Alex Rosenberg, who recognize that such an "emergent properties" materialism is actually a rejection of materialism.


* The more I study Marx and Engels, the more I suspect that what they meant by "materialism" does not closely match what scientistic materialists mean by "materialism" at all. When they rejected Hegel's "idealism," what they were rejecting was his notion that history is directed by the "big ideas" of Geist. What they pointed to instead was the "means of production": hand plows, water mills, steam engines, and so on. But of course all of those things are first and foremost ideas, that are then implemented in matter. So for them, "materialism" meant that ideas that result in concrete material objects are the primary drivers of historical development, and not ideas like monotheism or democracy.