What if you are Jewish and are trying to stop a Hitler from coming to power and the best means would be to spread a deliberate lie about him. Are you saying that the worse the outcome would be, the less likely you would be to lie?
Nobody in this discussion is confronting a present or potential totalitarian state bent on murder so this feels like a tangent. In fact, this is a hypothetical that very few people are ever confronted with and therefore it isn't relevant to a question of practical ethics. Very few people are skilled enough at predicting the future to know when the situation is dire or whether dishonesty will work; very few people are skilled enough manipulators to pull it off.
For the range of social issues the participants in this conversation are likely to confront, I think it's a good policy to be more careful and honest the higher the stakes. Among other things, the higher the stakes, the likelier a lie or mistake is to be caught. And being caught lying doesn't generally achieve any goal of the liar.
Obamacare only became law because Obama lied by saying that under the law "If you like your health care plan, you can keep it." PolitiFact made this their lie of the year.
I suspect that many on the left knew at the time Obama was lying about this but kept quiet because they really wanted the law to pass. They won.
Scott, known on LessWrong as Yvain, recently wrote a post complaining about an inaccurate rape statistic.
Arthur Chu, who is notable for winning money on Jeopardy recently, argued against Scott's stance that we should be honest in arguments in a comment thread on Jeff Kaufman's Facebook profile, which can be read here.
Scott just responded here, with a number of points relevant to the topic of rationalist communities.
I am interested in what LW thinks of this.
Obviously, at some point being polite in our arguments is silly. I'd be interested in people's opinions of how dire the real world consequences have to be before it's worthwhile debating dishonestly.