<i>Morals that are not backed by reason are on shaky grounds.</i><p>I'd say that's exactly what the moral realm is-- the area where reason fails us. Like you, I don't see much point in arguing about non-rational propositions; it's just two people contradicting each other.<p>I disagree with you about "white lies," though. In the limit, sure, I'd lie to save my brother from kidnapping, or that sort of thing. But most of the time, I'd rather deal in the truth, even if it makes people a little unhappier in the short term. For example, I'd rather hear "Your startup has serious problems X, Y, and Z that you had better fix before you launch," than "Looks great. I'm sure it will be bigger than Google," if the problems are really there.