Chess playing computers

While we might learn a lot about chess from the behaviour of a computer, and might learn how to play from such a computer, we cannot define chess in terms of the computer's behaviour. The rules of chess determine whether the computer is playing correctly - they are not tested against the behaviour of the computer.

This is also true of people: we might believe that people act rationally, but we cannot define rationality in terms of the behaviour of any individual or group - however apparently exemplary.

This extends to their internal 'behaviour' - no neurological account of brain processes can capture the normative aspects of rationality, just as no actual 'or' gate could count as the effective standard for the logical operator.

Under certain circumstances, we might have to choose between deciding that the standard meter had grown or that our prior measurements all needed to be proportionally corrected. If we standardise the meaning of 'or' on the behaviour of an 'or' gate, the meaning of 'chess' on the behaviour of a computer, or the meaning of 'rationality' on either a neurological process or the behaviour of an individual or group, we do not know what adjustment this might lead us to have to make - we do not know what changes in meaning we might have to accomodate.

The standard metre can only change in one way, resulting in a uniform scalar adjustement to length. The standard 'or' gate could change the meaning of 'or' in a way which rendered the world unintelligible.

The standard chess computer might redefine chess in terms of any option available to it - whether or not it was functioning correctly.