There is a time and place for everything. There is a time to speak and there is also a time where you should voice out your thoughts. Always remember the rule of thumb "When you can't say anything nice, say nothing at all". Your silence does not mean that you submit yourself to the person you are talking (or arguing) to, this means that you are strong enough to control yourself before you say things you might regret.
Words are powerful love, these are one of the things you can never take back once you said it, so before you do something rash, stop and think first.