THE HORIZONTAL RELATIONSHIP

In deciding what to say on the line below, not only must the points you include answer the question raised by the point above, they must also answer it logically. That is, they must present a clear inductive or deductive argument, one or the other, but not both at once. These are the only two types of logical relationship possible in a grouping.

A deductive grouping presents an argument in successive steps. That is, the first idea makes a statement about a situation that exists in the world today. The second idea comments on the subject or the predicate of that statement, and the third idea states the implication of those two situations existing in the world at the same time. Thus, the grouping would have the following form:

- Men are mortal.

- Socrates is a man.

- Therefore Socrates is mortal.

To move up a level of abstraction front a deductive grouping, you summarize the argument, with your summary resting heavily on the final point: "Because Socrates is a man he is mortal."

An inductive grouping, by contrast, will take a set of ideas that are related simply by virtue of the fact that you can describe them all by the same plural noun (reasons for, reasons against, steps, problems, etc.). The form of this argument would be:

French tanks are at the Polish border.

German tanks are at the Polish border.

Russian tanks are at the Polish border:

To move upward here, you draw an inference based on your assessment of what is the same about the points-i.e., they are all warlike movements against Poland. Thus, your inference would be something like "Poland is about to be invaded by tanks."

If you choose to answer the question raised by an idea deductively, you know you must have an argument in which the second point comments on the subject or predicate of the first, and the third point draws a "therefore" from the previous two. If you choose to answer inductively, you know the ideas in the grouping must be logically alike and can be designated by a plural noun.

Given this knowledge, you could start to build your pyramid anywhere, with a single idea, adding the other ideas as they are demanded-either up or down or sideways. But there is one more thing you need to know before you venture off to build a pyramid of your own. And that is the beginning question to which your document must give the answer. You determine that by tracing the narrative flow of the introduction.