Deep Thought time again, on the nature of honesty. How important is it for a person to develop an internal commitment to the truth? How important is it to be truthful even if no one else will ever know if you lied?

Suppose a friend gets a haircut that you think is the ugliest thing you've ever seen, and she asks your opinion?

Suppose the truth is X, but you couch it in such a way that any reasonable person would assume Y; and you know your listener understood Y, and you didn't correct him? Is that lying?

What would you be more likely to lie about: something you did that was wrong, or something you did that makes you look stupid and hurts your pride?

Could you ever trust someone you discover to be a facile liar? Suppose you only catch him lying about things that don't matter?

Is there a connection between being careful to be truthful to others, and being truthful with onesself? We're all familiar with Polonius's advice: "This above all: to thine own self be true, and it must follow, as the night the day, thou canst not then be false to any man." But does it work the other way, too: if a person is scrupulously truthful to other people about how much she drinks, or smokes, or gambles, or wastes time surfing the net (ahem) is she less likely to drift too far down the garden path?