A Turing test...
... in which the investigator is able to ask a number of questions of a Noble Lord to ascertain if there is any sign of intelligence within.
But seriously, folks, even as a lifelong fan of Turing (it's not just computing - check out what he did for developmental biology) and a strong believer in gay rights, I'm in two minds about this pardon business. I agree with JGC on why he couldn't support the second petition:
But I think there's also an important semantic difference between a pardon and apology - it seems to me the apology is the stronger response.
A pardon *could* be read as "OK, you *were* guilty of gross indecency, you nasty little sodomite, but because you did all this other cool stuff we'll rather pointlessly let you off". Whereas the apology quite clearly says "OK, we can't undo the past, but we do recognise that the law at the time was abhorrent".
So the pardon *could* still exist in a system in which the law at that time is still considered valid and moral now, and his (supposed) moral guilt for homosexuality is just outweighed by his other gifts to society. The apology is stronger because it unambiguously and entirely transfers any guilt (vicariously) to the government of the time.
Does this make any sense?