Is the brain alone necessary and sufficient to cause the mind? Here’s a thought experiment:
Imagine scientists living on an isolated island who have developed sophisticated science and culture, with one exception: they deny that telecommunication is possible. For assorted reasons, they deny that the human voice can be transmitted through space, except as vibrations in air. We’ll call this civilization the ‘Verizon Deniers.’
One day, they find a cell phone (it dropped from a plane or something). They turn it on, and they hear things. They hear hissing, cracking, and what sounds like voices!
The Verizon deniers are amazed! So it’s off to the lab, and soon the Verizon denier scientists have the answer. They show that all kinds of things — chemicals, mechanical impacts, electrical interference — can change or ablate the voices. They find that certain sounds the voices make are consistently associated with patterns of activation in the cell phone circuits. They found that some aspects of the voices — tone, amplitude, etc. — are localized within the cell phone. They conclude that the voices are simply an emergent property of the cell phone circuits!
However, one of the scientists, a Verizon accepter, isn’t so sure. He says:
“What if the cell phone is necessary for all of the noises, but only sufficient for some? What if some of the noises in the phone are actual voices of living people, and are merely transmitted through the phone, but not caused by it?”
The Verizon deniers say: “How can you prove it?”
So the Verizon accepter goes to work. He studies the properties of all of the noises the phone made. Some of the noises, like the hiss or the cracks, he can explain as an emergent property of the phone — just oscillations from the circuitry transmitted through the speaker to the air.
But the voices are different. The sound of the voices certainly has some properties like those of the circuit — frequency, amplitude, power, etc — but there’s more to them. They have meaning. These ‘voice’ noises express anger, love, purpose, judgment — all properties that are not inherent to electrical components.
So the Verizon accepter decides that the voices are not caused entirely by the cell phone. He concludes:
1) The cell phone is necessary for all of the noises
2) The cell phone is sufficient to produce noises that only have properties — like frequency and amplitude — that are shared with the circuitry in the cell phone itself
3) The cell phone is insufficient to fully account for the noises (i.e., the voices) that have meaning, because meaning is not a property of matter. The only thing that can cause meaning is a person.
The Verizon accepter shows that there is a method of determining whether the mind can be caused entirely by matter. If the mind has a property, such as meaning, that is not a property of matter, then matter, while perhaps necessary to the mind, is insufficient to cause it.
Too simple? I propose that any credible theory of the mind must at least provide a basis for discerning that a voice from a cell phone is generated by a person, not the phone. It’s a kind of inverse Turing test — it tests the theory, not the machine. As I see it, none of the materialistic theories of the mind would provide a clear basis for identifying the voice in a cell phone as a person and not as an emergent property of the phone. If a theory can’t get a cell phone right, I don’t trust it with the mind.
So, you ask, what was the denouement of the story about the scientists on the island? Well, things went well for the Verizon accepter, until he applied for tenure…