Finally a sharpening thread I can contribute to. First of all it is not how sharp the tongue, it is how motivated the application. I have found through experience that the one fatal mistake that can get a sharp tongue to be dangerous is not so much being logically , as in mathematically , positively right . It is that you took the time and trouble to prove that you are right and to have had the poor foresight to "show your work". Welcome to the land of unexpected consequences , even if you SHOULD have expected them. Do not go down this path. If you find yourself right , apologize at once as this is the one most cardinal sin. Swallow that pride , pull back from the line you draw in the sand and erase it immediately, muttering "I could be wrong though" as you do. Remember , stress can shorten your life and stress is what you shall reap , a poor exchange for the dubious pleasure of "winning that one". That win is an illusion ,it will be paid for repeatedly and for longer than you might believe possible.