Using Syllogisms to Plan an Essay

Before writing your essay, you  should prepare an outline that orders your argument as you will present it.

To form an outline, analyze the syllogisms that form your argument and decide which premises to defend. Your thesis statement, in setting out the one main argument, sets out the one main syllogism. Your entire essay aims to prove the conclusion of the main syllogism by proving the truth of the premises. In other words, to establish the claim of your thesis, you must use the body of your essay to argue for the evidence on which your conclusion rests. As a result, your outline will include one main syllogism and several other syllogisms supporting it.

But how do syllogisms help you build an outline? They show you which premises you should defend in the body of your essay. 

Let’s say you are writing an essay that makes the following basic argument: 

All M is P

All S is M

Therefore, all S is P

Let’s assume that, of the two premises, All M is P is obvious and need not be stated, while All S is M requires proof. (This does not always happen. Sometimes both premises require proof, and if both require proof then you must defend both in the body of your essay.) 

Your thesis will state both the conclusion and the important premise to be proved; the body of your essay will prove that premise.

Thesis Statement: All S is P (claim) because all S is M (evidence).

Body: proving the evidence

Paragraph #1: All S is M. 

Proof: The inductive method. List examples of times when all S is M.

Paragraph #2: All S is M. 

Proof: If P, then all S is M. 


Therefore, all S is M.

Paragraph #3: All S is M. 

Proof: Either all S is L, or all S is M. 

S is not L.

Therefore, all S is M.

Paragraph #4: All S is M. 

Proof: All J is M. 

All S is J.

Therefore, all S is M.

This very abstract example will become clearer if you examine the sample exercises in the following section.