Question:
I heard you explain that harmless lies are also bad. You explained that "truth" is the Divine brand and that we should always strive to be completely honest. But surely that is not always the case. If my wife says to me "do I look good in this new dress?", do you really expect me to answer: "to be honest, you look shocking"? Isn't lying sometimes the better (and safer) option?
Answer:
Although honesty is admirable and ethical, it is not an absolute value. There are instances when it is permitted and even encouraged to alter the truth.
Some examples:
a) Protection of dignity and pursuit of peace - If being honest will insult or hurt another person or cause discord among friends it is better to tell a white lie. When G-d spoke to Abraham He intentionally misquoted comments that Sarah had made because the accurate version might have hurt Abraham. The Talmud tells us that Aaron the high priest would tell untruths to get enemies to make up.
b) Humility - It is permitted to deny the extent of one's knowledge in order to be humble and prevent feelings of arrogance and conceit.
Lying is evil for a reason. Honesty achieves certain goals like trust, stronger relationships, humility and Divine connection. But when the very goals of honesty are undermined by being straight, then the truth is useless. If we end up causing pain, creating discord or breeding arrogance, then an alternative path must be sought to achieve the goals of honesty.
So if your wife or friend asks for your opinion about a dress before she buys it, be brutally honest. But if it is after the fact, you have two choices. Either learn to like it or hide your true feelings. Saying it like it is will only hurt her and undermine the value of truth.
(A word of caution: It is very easy to use this theory to justify illegitimate lying. We need to be absolutely certain that lying is the only option.)
We should always strive for truth. But let us also remember the teaching of the Talmud, that there are two things that cause G-d to be amongst us - peace and humility.