Since a topic sentence operates exactly like a thesis statement but on a smaller scale, a topic sentence must conform to all the rules we laid down earlier for theses. In other words, a topic must not be questions must not contain "I think" or "I feel," must not be a blanket statement, must not contain unrelated elements, and must not contain obscure or garbled language. By adhering to these guidelines, you will ensure that a topic sentence effectively presents the main idea of your paragraph.

Example

Consider the above case in which we discussed a hypothetical essay on women in combat. Let's go through an exercise that will effectively show how we can develop solid topic sentences from the thesis statement "Women should not serve in combat." (*Note: Please do not take this example as an instance of sexism. The topic is a fruitful one for discussion as it brings such strong responses from most people.)

The first thing to do is examine the thought process we went through when we conceived the thesis statement. In other words, we need to ask ourselves why we believe that women should not serve in combat. The best way to do this is to return to the diagramming method we used previously, the one that helped us come up with a thesis statement in the first place.

In this case, we would begin with a clean sheet of paper, place our thesis statement on the center of the sheet, and surround the statement with a circle.

Next we would ask ourselves why we believed that statement to be true. As we came up with the reasons, we would simply arrange them around the thesis statement and connect them to it.

So, through the diagramming process, we have come up with three major reasons why we believe that women should not take part in combat.

1. Women are physically weaker than men;
2. Men would be less effective in combat if women were around; and
3. The American tradition does not support women fighting in wars.

Each of these reasons can be used as topic sentences, provided they don't violate any of our basic rules for thesis statements and topic sentences (and, of course, each actually is a sentence). A quick check is easy to perform.

• Are any of these reasons questions? No.
• Do any of these reasons contain "I think" or "I feel"? No.
• Are any of these reasons blanket statements? Some might think that "Women are physically weaker than men" is a blanket statement, but the proposition is arguable. (Some women are quite strong, and some men are quite weak.) So, no, none of the reasons are blanket statements.
• Do any of the reasons contain unrelated elements? No.
• Finally, do any of the reasons contain obscure or garbled language? No.

Therefore, these reasons will work as solid topic sentences in support of the thesis statement "Women should not serve in combat." If our answers to any of the above questions were "yes," then all we would have to do is rewrite our reasons so that they conformed to our standards.

Now, the process of formulating topic sentences is different from the process of formulating a thesis statement. When we arrived at a thesis statement, we needed only one, so order was not a problem. However, when we formulate topic sentences, we will need for each body paragraph of our essay, and we also have to determine an order for these topic sentences (and thus our paragraphs).

As conscientious writers, we want to arrange our compositions so that their arguments have the maximum effect on our readers. An important facet of organization is the order in which we present our paragraphs. We could go from the least strong to the strongest point, for example. However, most of the time our own ideas will seem to have a sort of order to them that is easy to see if we examine them.

A good way to examine the major points of our argument is to look at them as they are arranged around the thesis statement on our diagram. Does any one necessarily follow another? Is the point made my one dependent on a point made by another? Does an order of presentation seem to spring out at you? No matter what the answers to these questions are, as conscientious writers, we should always have a plan behind our composition. What the plan is will vary widely from work to work, but the plan will always arise from a serious examination of your topic sentences.

In this case, our topic sentences do present a sort of natural order, that of specific to general or general to specific. "Women are physically weaker than men" is rather more general than "The American tradition does not support women fighting in wars."

If we decide to arrange our topic sentences (and thus our paragraphs) from general to specific and wish to see how such an arrangement would work in our paper, and extension of our earlier diagramming procedure can be very helpful. A tree diagram is similar to our earlier diagrams but has a slightly different format, one that reflects the order in which our arguments will be presented and also shows their relationship to our thesis statement. A tree diagram shows a general-to-specific organization of our three topic sentences.

The tree diagram has many advantages. First we can examine the diagram from top to bottom to see how we plan to prove our thesis statement. Everything below the thesis statement is an argument in support of our thesis; the diagram allows us to examine our argument visually to see if any of them are weak or out of place or simply do not prove anything. Second. we can examine the diagram from left to right to see the order of our ideas. We have here decided to move from the general to specific, and thus the topic sentence furthest left of our first and also most general idea. As we move right, our ideas become more specific. If our order does not suit purposes, a visual examination of the diagram will quickly tell us so.