That's not what I said, and it's the least sophisticated way I saw to phrase it to engage your argument in a precise way. The closest thing to your summary that I would accept is, "words can't convince people to do arbitrarily crazy things, in a way that you can predict."

> If you had [superintelligence], you could turn it on the question of "what would this human choose to do if I were to give them instruction X" for any X ... But I don't think I really need to provide support for the idea that something superintelligent would also be able to predict the actions of people under pressure in the same way someone of moderate intelligence can predict the actions of fluids under pressure.

So can humans predict these things to a degree. But even having perfect prediction (which I contest with (1)) does not entail perfect control, just by continually computing the effect of, and refining, your X.