Questions of character should be raised in political debate if they are relevant to the opponent's argument. Debating techniques that do not confront every argument should be avoided. Attacks on an opponent's character result from an inability to confront the opponent's argument properly. Attacking the character of one's opponent does nothing to preserve one's moral right to enter into further political debates.
Attacks on an opponent' s character should be avoided in political debates. Such attacks do not confront the opponent' s argument; instead they attempt to cast doubt on the opponent' s moral right to be in the debate at all.
Which one of the following principles, if valid, most helps to justify the reasoning above?