Mind: A Brief Introduction (John R. Searle) / quote 68 of 138
The brain as a universal Turing machine
Turing, in an important mathematical result known as Turing’s Theorem, proved that there is a Universal Turing machine that can simulate the behavior of any other Turing machine. More precisely, Turing proved that there is a Universal Turing machine, UTM, such that for any Turing machine carrying out a specific program, TP, UTM can carry out TP. What made these ideas so exciting was the following thought: Suppose the human brain is a Universal Turing machine? I cannot exaggerate the excitement that this idea generated, because it gave us at long last not just a solution to the philosophical problems that beset us, but it gave us a research program. We can study the mind, we can find out how the mind really works, by discovering which programs are implemented in the brain. An immensely appealing feature of this research program is that we do not actually have to know how the brain works as a physical system in order to do a complete and strict science of the mind.