Take ownership of your choices. The best way to do this is to keep your reasons, proofs, explanations, and defensive evidence to yourself. The supreme proof that your choice is right comes in the resulting aftermath.
Those who keep their silence until the ending evidence has the last word—through slander, provocative accusation, gossip, doubt, even coup and impeachment—will be left standing after the dust clears. There’s a time to talk, especially to delineate decisions and implement action, but that is different from babbling on about the justification and rationale for what you do. Of course, a little philosophy about why you do what you do won’t hurt, as long as you’re not using philosophy to build a case in your defense or trying to prove that an idiot is an idiot.
Just talk as you need in order to finish the task at hand. Don’t fall for the trap of someone asking you why you did what you did as a way of convincing you to do something differently. If you are a fool and headed in the wrong direction, listen to the voice of wisdom, but don’t change merely because someone debated your reasons. If you should change, proof that another way will succeed requires no discussion about your reasons for the failed method. That works in reverse as you deal with other people.
Keep your eyes on your own path, never why another path is wrong—and never let others tell you why your path is wrong, but only why another path might be better. Once you’ve heard them out, make your decision and press on. Don’t explain yourself; friends don’t care and enemies won’t accept your reasons anyway.
When you reject “indefinite discussion until others agree with you”, those others will call you “unfriendly”, when the underlying issue is that you disagree. Stay on task. Actions speak louder than words, let them.
Get a reputation so people already know your answer when they ask why you do what you do, “Because I want the results that follow.” Eventually they will stop asking, then you can focus on your task. If you deliberate, it’s because you value discussion more than results.