As we saw in Dr. Syntax 7, an argument as a whole has a structure similar to that of a paragraph: its thesis statement is like a paragraph’s topic sentence, and each topic sentence functions, just as a paragraph’s sentences do within the paragraph, to prove the thesis statement. You achieve internal unity and coherence in an argument, therefore, as you do in a paragraph: by setting up clear relations. The argument will be unified if each paragraph, through its topic sentence, is clearly related to the thesis statement; it will be coherent if each of those topic sentences has a clear semantic relation to the previous one. Looking back over our exercises, you can see that all of them stress relations; we’ve built from the syntax of the sentence, to the “syntax” of the paragraph, to the “syntax” of an argument.
When you are revising an argument, you can easily check its unity and coherence by writing the following kind of outline of it. First, write out your thesis and, to keep yourself on track, analyze it for the topics with which you must deal and for the the relationship(s), your line(s) of argument, among those subjects. Write them down. Next, use your actual topic sentences to make an outline of the current form of your argument. That is, the actual topic sentences will be the major parts, indicated by Roman numerals, of the outline; you need not include the proof of each topic, that is, the sentences within a paragraph. The chances are pretty good that when you finish the outline, you’ll see that some part or parts don’t in fact have an evident relation to the thesis or to each other. What you do now depends on what the problem is: you may need to revise your thesis to include the idea contained in a stray topic sentence, or you may need to restructure a topic sentence so that its relation to the thesis statement is clear, or you may need to write an additional topic sentence and paragraph to cover some part of your thesis which you now realize you’ve omitted, or, worst of all possible cases, you may have to throw out an entire paragraph, because it’s irrelevant to what you’re trying to argue. But you do end up with a much more effective argument!
Exercise: Please type this exercise. Using multi-paragraphed argument you have already written for one of your classes, write out your thesis statement, subjects, lines of argument, and make an outline from your topic sentences. Check what you have for unity and coherence. Next, make whatever revisions are necessary for a hypothetical new argument and write the outline of that new argument. Turn in the argument you use and both of your outlines.