Quite so, Lighter. Moral questions are one area, negotiations are another, and there are more. What I think these things have in common is that the true/false dimension is not really the appropriate one. You can force them onto true/false, in most cases, but it is usually a bit artificial to do that. It is interesting to note that moral philosophy often says a lie is 'the intention to mislead', which is quite a different thing to a falsehood. If I remember correctly, Iago never told Othello a falsehood in Shakespeare's version of the story: it was all about deliberate misleading.