What will help our argument 'see light' (line 17), according to the passage?

Direction:

            Whether the argument is oral or written, the active purpose
            is to make the other person take your view of the subject.
            In an explanation we put forth our personal attitude before
            others but in an argument, we realize people are having a
(5)        different view on the same subject. So we use two weapons –
            one is of conviction and the other of persuasion. We try to
            prove the authenticity of our criteria by convincing others,
            using practical examples so that the other party comes round
            to our point of view. We also use moralizing to bring more
(10)      partisans to our view. But when this lacks practical touch it
            can be called persuasion. If you put forth that the shape of
            hills in New England is due to glaciers, you are first trying
            to persuade. Since here logic is lacking, it cannot be
            convincing. Human thinking and feeling also comes to rescue.
(15)      The first reaction could be spontaneous due to feeling but
            reasoning does come later. So in all arguments one must
            keep in mind both the forces so that our criterion sees light.