Is it ever appropriate to manipulate people on the assumption that they are unreasonable? It strikes me as problematic, but it's also exceedingly common. Just think of all the white lies we tell to avoid causing offense, or the rhetoric of a political partisan who doesn't trust her compatriots to listen to reason alone, or the general practice of trying to impress people through non-rational means, say by dressing up. (Monogamy itself may be another example.) I assume none of these would be necessary if people were just a bit more reasonable. But if our pessimistic predictions are accurate -- as they often are -- is that enough to justify acting on them?
I suggested before that the assumption of unreason denies agency to the target. Sure, people are often unreasonable. But not inherently so. Anyone could do better, if they made the effort. And wouldn't they be the better for it? The choice is theirs, and insofar as people live up (or down) to expectations, we should do our bit to help them make the best choice, by expecting nothing less of them.
The alternative is to treat them as a mere object, disrespecting their rational autonomy. By taking it upon yourself to effectively make their decisions for them, you turn them into something less than fully human. Unless, I suppose, they were already that way to begin with. If someone truly is unreasonable, then they have no rational autonomy for you to usurp. They are animals already; you may as well make them comfortable.
What about the more realistic case of a person who is merely unreasonable in a few particular respects? (That presumably covers all of us!) Are we to pretend that we're all perfectly rational agents? That seems dishonest, and silly besides - the pretense surely wouldn't last long. Still, it at least seems like an ideal to aspire to; and cause for mild embarrassment insofar as we fall short. Anyway, the question is: how should others relate to us in those specific cases where we are predictably unreasonable? Two responses suggest themselves.
(1) They could accommodate our unreasonable natures, as is standard practice. But, as noted above, this seems disrespectful -- at least if they cannot be certain that we wouldn't have risen to the occasion.
(2) They could demand perfection from us. (It would be ridiculous to expect perfection always, of course. Nobody can deliver that. But perhaps it is reasonable to demand the best in each particular case, even recognizing that there's no way we can manage this in all of them. Note the difference: we are bound to screw up sometimes, but not any time in particular.)
Given the fundamental value of autonomy, perhaps what really matters here is ensuring that we improve in this respect as much as possible. It's then an empirical question what the most productive response to failure is.
Or is it unreasonable of me to place such value on reason?