Enthymeme means "in mind, in thought." It is an architectonic principle. Like the principles of architecture which guide one in the construction of a building without (for the most part) insisting on the specific shape of the building, an enthymeme guides an academic writer in the composing of an essay without insisting (for the most part) on the form that essay will take. An enthymeme is certainly not a mold into which one pours an essay, and an enthymeme need not be explicitily stated for the reader. But a reader must be able to infer the enthymeme guiding an essay if it is not stated, and a writer, of course, must know his essay's enthymeme in order to know the assertion and proofs that need to be given to the audience.

1) An enthymeme has two basic components: an assertion and a reason (also called the "because clause"). The assertion is the point of the paper, the claim or thesis. The "because clause" is the reason why the audience should accept this assertion.

Example: I received a parking ticket because I forgot to put money in the parking meter.

     Assertion: I received a ticket.

     Reason:    I forgot to put money in the meter.

2. Both the assertion and the reason must be independent clauses. Each idea must be able to stand by itself as a sentence.

          Idea 1    because     Idea 2 

          Idea 1    therefore    Idea 2

Example: Star Wars remains immensely popular because it reiterates the classic tale of the individual hero's triumph over totalitarianism.

   Idea 1--Star Wars remains immensely popular.

   Idea 2--Star Wars reiterates the classic tale of the individual hero's
           triumph over totalitarianism.

3. The reason and the assertion must have shared logical terms. This means that the subject of the assertion must be the same as the subject of the reason. An easy way to think of this is to use the equation A+B=A+C. The "A" is the shared term ("Star Wars" in the example above) while the "B" and "C" are the elements of the clauses that are different from each other--the center of the assertion and the reason. However, though shared logical terms are important, this does not mean that the exact same word must appear in both the assertion and the reason. Instead, even though the subject of the assertion and the subject of the reason are the same, they may be stated in different words (for example: it, he, she, those, these, they...).

4. The assertion and the reason must be different. If the reason is simply a restatement of the assertion, the thesis is circular argumentation. Circular reasoning (also called a tautological argument) may occur in both the positive and negative form. That is, an enthymeme is circular if the reason simply repeats the assertion. It is also circular if the reason is a statement which is the negative of the opposite of the assertion.

Example of a circular argument in the positive:
     Bike laws are too strict because they are rigid and prohibitive.
Example of a circular argument in the negative:

     Bike laws are too strict because they are not flexible or
permissive.

5. The assumption which connects the assertion and reason should be an assumption accepted by everyone, even someone who holds the opposing viewpoint. (In some cases, an author will state the assumption; in other cases the assumption is implied. Either way is acceptable.) The assumption is the common ground from which you and the opposition begin the debate. Without common ground, it is impossible to persuade your opposition to accept your assertion.

Example of a thesis based on an unacceptable assumption:
     She could not have committed this horrible crime [because] 
     I have known her since she was a child.

The assumption which connects the reason and assertion is "No one I know
could commit a terrible crime."  Most of us would disagree with this
assertion: simply because you know someone does not mean that that person
is incapable of committing certain crimes.

6. The enthymeme should answer a question at issue. A "question at issue" is a question about which there is disagreement in your discourse community. Furthermore, a "question at issue" addresses an issue about which your discourse community truly cares--an issue which directly effects your discourse community.

There are two primary reasons why a question would not be "at issue."
    A)The question is not one about which the audience truly cares; the
question has little to no direct influence on the lives of the people at
whom the argument is directed.  For example:   The British government 
should reform the tax rates on personal income because exorbitant taxes
are responsible for England's low standard of living. 

     B) There is little disagreement about the answer to the question.
For example: The University should not allow the government to build a
toxic waste site on campus because toxic waste is hazardous to human
health.

7. Often, differences of opinion occur because we define certain words differently. In the abortion debate, both sides define "life" differently. Does life begin at conception, or does it begin at birth? In gun-control debates, both sides define our Constitutional right to bear "arms" differently. Does "arms" mean all types of guns, including automatic assault weapons, or does it mean something more limited? Furthermore, because the enthymeme is the heart of your argument, your working definition of all words in the enthymene must be clear. This may be done by rewording the enthymeme or it may be done in the body of your paper. Usually, both are necessary.

Example: Athletic scholarships are unfair because they use money that
could be better spent.

Words such as "unfair" and "better" are highly subjective.  In fact, it is
likely that we each have different standards for what is "fair" and
"unfair."  Furthermore, "better" implies a comparison.  Yet, in this
enthymeme, no comparison is provided.

Example: We should provide fewer athletic scholarships and more
academic scholarships because the university has an obligation to educate
students, not to train athletes.

This second enthymeme is clearer than the first, because its language is
more concrete.  However, as with all language, the words in this enthymeme
are still subject to interpretation.  Therefore, it may be necessary for
the author to define, explain, or provide examples to make the meaning
more apparent.  For example, what is meant by "fewer" and "more?"  Does
the author have a reduction or increase of a certain percentage in mind?
Or, what is meant by "obligation?"  How are the obligations of an
institution determined? What does it mean to "educate?"  Is education
strictly intellectual?  Many or all of these questions may be addressed in
the body of the paper.

8. Once you have produced a properly constructed enthymeme, you are ready to begin structuring your argument. The primary purpose of this argument will be to "prove" your reason, not your assertion. If you "prove" the reason, and if the assumption is readily acceptable, then you will have provided a persuasive argument in support of the assertion; you will have earned your conclusion.