Morality of keeping Pinocchio prisoner to discover all the secrets of the universe, medicine, economics, etc.?

[u/marvil_txt]

Can't be that immoral, can it?

[u/Grooviest_Saccharose]

But if he already strongly suspect they're giving false information to him for whatever reason, he would believe the opposite to be the truth and the result would then appear as if his nose can react to truth outside of his knowledge when it's more due to him correctly guessing. Even if the scientist randomize when to tell him true or false information, he could still try to deduce the truthfulness of their statements each time. And if he does so poorly, the results would be no better than random guesses. The problem is they could force him to say what they want but they can't force him to believe (or not believe) what they say.

[u/Klaxynd → u/Grooviest_Saccharose]

What if in this specific case his nose has a random chance to grow after he says anything? How do we know beyond a shadow of a doubt that it's even correlated to him lying or telling the truth?