Lies

What do you consider a lie? Or should I ask, how much truth you hide till you consider that lying? I read that the "perfect" lie contained mostly truth. You just "modify" some details. If you didn't make up anything but just hiding the truth, does that consider a lie? A half truth, is that a lie? I was talking to a friend today and I told my friend that he may hurt another person if he does thing the certain way. He said he is saving the person from truth from getting hurt. Does white lie consider a lie? I know people think white lie is for the other person's own good. How do you know you are really know what the other person want? What if lying actually hurt the other person more? We lied because we think the other people will never find out the truth. Are there lies that can keep in secret forever? What if the other people find out and it actually hurt them more? I know people said lying depends on circumstances and people. And the world actually despise people who tell truth. My mom always said that my dad is a true Canadian because he is too honest. Is honesty a bad thing now? I thought our parents always teach us to be honest when we were young. And now honesty depends on circumstances? Or this whole world is just messed up? That we have to lie in order to survive or you may get backstab by other people?