I try to call liars on their lies, although I suppose in some situations, it would be better to confront them privately than contest a lie in public as it is spoken.
If I had to deal with a habitual liar, I would strenously call any lies ever heard, presenting the correct information. Perhaps the habitual liar would then learn that it doesn’t pay to lie.
However, I’d rather not have to judge habitual liars since while some lie for profit and gain, some lie to avoid embarrassment and some are deeply embedded in their fantasies. Others may have a blurred sense of truth. The intention to cause harm by distorting the truth is not always present. Perhaps not very often, actually.
Some liars are difficult to catch since they will go to great lengths asserting that they speak the truth. They will make you look bad if you don’t believe them. Sometimes you will give them the benefit of doubt in spite of overwhelming odds of probability.
Well, there’s always the possibility that asking him directly will work. “Why do you lie?” Sometimes simple solutions work the best. Who knows, maybe he will actually answer and give you some insight in the situation.
I would think lying in unimportant matter suggests a blurred distinction of truth and falsehood, which probably means that empirical facts are not so important to the person. I would say it’s possible such an attitude comes from very bad experience with the real word. It must be very sad for the person. It should be better to approach him with care and love rather than a justice-based confrontation. At the same time, the lies should never be “bought”, I think. But this might be just my reluctance to tolerate such things. At any rate, I would approach the person with care, but never allow the lies to pass unchallenged. Also, perhaps the experience with the habitual liar of a girlfriend has changed him. That must have been quite traumatising for him. I can imagine… I had a kind of relationship like that some time ago.