Well that's not fair, generating hypotheses that fit an observation is sometimes useful, as Harry&Draco did when finding some that fit magic getting weaker. The philosophers, when acting as oracles, should not have to entertain the possibility that the assumptions given to them are wrong.
In general, considering how many wrong assumptions there are, I think it's good practice to check the assumptions one has been handed.
On the other hand, it's probably not fair for kings to play that sort of game.
Another month, another rationality quotes thread. The rules are: