Well, I agree that the value of Alice’s testimony is null. However, depending on the answer to my original question, the value of her argument may also become null. More specifically, if we assume that Alice would have made an argument of similar quality for the opposing side had it been requested of her by her boss, then her argument, like her testimony, is not dependent upon the truth condition of the statement “There is no largest prime number”, but rather upon her boss’ request. Assuming that Alice is a skilled enough arguer that you cannot easily distinguish any flaws in her argument, you would be wise to disregard her argument the moment you figure out that it was motivated by something other than truth.
Note that for a statement like “There is no largest prime number”, Alice probably would not be able to construct a convincing argument both for and against, simply due to the fact that it’s a fairly easy claim to prove as far as claims go. However, for a more ambiguous claim like “The education system in America is less effective than the education system is in China”, it’s very possible for Alice’s argument to sound convincing and yet be motivated by something other than truth, e.g. perhaps Alice is harbors heavily anti-American sentiments. In this case, Alice’s argument can and should be ignored because it is not entangled with reality, but rather Alice’s own disposition.
This advice does not apply to those who happen to be logically omniscient.
Well, I agree that the value of Alice’s testimony is null. However, depending on the answer to my original question, the value of her argument may also become null. More specifically, if we assume that Alice would have made an argument of similar quality for the opposing side had it been requested of her by her boss, then her argument, like her testimony, is not dependent upon the truth condition of the statement “There is no largest prime number”, but rather upon her boss’ request. Assuming that Alice is a skilled enough arguer that you cannot easily distinguish any flaws in her argument, you would be wise to disregard her argument the moment you figure out that it was motivated by something other than truth.
Note that for a statement like “There is no largest prime number”, Alice probably would not be able to construct a convincing argument both for and against, simply due to the fact that it’s a fairly easy claim to prove as far as claims go. However, for a more ambiguous claim like “The education system in America is less effective than the education system is in China”, it’s very possible for Alice’s argument to sound convincing and yet be motivated by something other than truth, e.g. perhaps Alice is harbors heavily anti-American sentiments. In this case, Alice’s argument can and should be ignored because it is not entangled with reality, but rather Alice’s own disposition.
This advice does not apply to those who happen to be logically omniscient.