It does not make such a difference whether you are simply mute or employ no art for speaking. For it is not feasible that you can express what you think as it should be understood unless you acquire and strengthen the ability to speak by art.
What do you believe was on the mind of the ancient Romans that they called the arts of speaking humanity? They judged that, indisputably, by the study of these disciplines not only was the tongue refined, but also the wildness and barbarity of people’s minds was amended.
Does the painter imitate the body correctly if he guides his brush without any method, and if his hand is moved at random and the lines are not drawn with art? In the same way you will not put the sentiment of your mind in front of the others’ eyes unless you use appropriate and distinct words, a fitting arrangement of words and the right order of sentences. For, just as we represent bodies by colours, we represent the sentiment of our mind by speech.