I. The purpose of discourse
II. The forms of discourse:
When we pause to look about us and to realize what things are really going on, we discern that everyone is talking and writing. Perhaps we wonder why this is the case. Nature is said to be economical. She would hardly have us make so much effort and use so much energy without some purpose, and some purpose beneficial to us. So we determine that the purpose of using language is to convey meaning, to give ideas that we have to someone else.
As we watch a little more closely, we see that in talking or writing we are not merely talking or writing something. We see that everyone, consciously or unconsciously, clearly or dimly, is always trying to do some definite thing. Let us see what the things are which we may be trying to do.
If you should tell your father, when you return from school, how Columbus discovered America on October 12, 1492, and should try to make him see the scene on shipboard when land was first sighted as clearly as you see it, you would be describing. That kind of discourse would be called description. Its purpose is to make another see in his mind’s eye the same image or picture that we have in our own.
On the other hand, if you wished to tell him the story of the discovery of America, you would do something quite different. You would tell him not only of the first sight of land, but of the whole series of incidents which led up to that event. If he could follow you readily, could almost live through the various happenings that you related, you would be telling your story well. That kind of discourse is not description but narration.
Suppose, then, that your father should say: “Now tell me this: What is the difference between the discovery of America and the colonization of America?” You would now have a new task. You would not care to make him see any particular scene or live through the events of discovery but to make him understand something which you understand. You would show him that the discovery of America meant merely the fact that America was found to be here, but that colonization meant the coming, not of the explorers, but of the permanent settlers. This form of discourse which makes clear to someone else an idea that is already clear to us is called exposition.
And now suppose your father should say: “Well, you have told me a great deal which I may say is interesting enough, but it seems to me rather useless. What is the purpose of all this study? Why have you spent so much time learning of this one event?” You would of course answer: “Because the discovery of America was an event of great importance.”