probity and personhood

The concept of an insincere or untrustworthy or fickle person makes sense. But only up to a point. For if one never kept one's word then what has the outward form of someone's word could no longer meaningfully be taken as such. This is the situation we meet with with serial liars. They have no integrity, and the effect of this is that their words - and their word - no longer mean anything. Such people sometimes fool themselves that their word yet means something - that they really are promising something when they utter words with a promissory form. Perhaps they 'feel an intention' inside themselves. Perhaps they imagine they can just 'know' this from within. Yet, as Wittgenstein says, 'an 'inner process' stands in need of outward criteria'. Such a person truly is just kidding himself; yet if he keeps at it eventually he won't even be a person kidding himself. He will have lost his soul.