Helmholtz didn't say a brain was like a telegraph; he was talking about the peripheral nervous system. And he was right, signals sent from visual receptors and pain receptors are the same stuff being interpreted differently, just as telegraphing "Blue" and "Ouch" would be. That and the spirit of the gods have no place on this list and strain the argument.
Hydraulics, gear systems, and computers are all Turing complete. If you're not a dualist, you have to believe that each of these would be capable of building a brain.
The history described here is one where humans invent a superior information processor, notice that it and humans both process information, and conclude that they must be the same physically. The last step is obviously flawed, but they were hardly going to conclude that the brain processes information with electricity and neurotransmitters when the height of technology was the gear.
Nowadays, we know the physical substrate that the brain uses. We compare brains to computers even though we know there are no silicon microchips or motherboards with RAM slots involved. We do that because we figured out that it doesn't matter what a machine uses to compute; if it is Turing complete, it can compute exactly as much as any other computer, no more, no less.
Hydraulics, gear systems, and computers are all Turing complete. If you're not a dualist, you have to believe that each of these would be capable of building a brain.
The history described here is one where humans invent a superior information processor, notice that it and humans both process information, and conclude that they must be the same physically. The last step is obviously flawed, but they were hardly going to conclude that the brain processes information with electricity and neurotransmitters when the height of technology was the gear.
Nowadays, we know the physical substrate that the brain uses. We compare brains to computers even though we know there are no silicon microchips or motherboards with RAM slots involved. We do that because we figured out that it doesn't matter what a machine uses to compute; if it is Turing complete, it can compute exactly as much as any other computer, no more, no less.