From the preceding suggestions it is seen that the subject of an argument is a definite, restricted thought derived from some general idea. Whether expressed or not, the subject must be a proposition, not a term. In debate the proposition is usually framed in the form of a resolution. This resolution must always be so worded that the burden of proof will rest upon the affirmative side. Nothing in the wording of the proposition should give either side any advantage over the other. These principles have to do with the manner of expression; subjects will next be considered with respect to the ideas they contain.

A common and convenient method of classification divides propositions into two groups: propositions of policy, and propositions of fact. The first class consists of those propositions that aim to prove the truth of a theory, that indicate a preference for a certain policy, for a certain method of action. The second class comprises those propositions that affirm or deny the occurrence of an event, or the existence of a fact. Propositions of policy usually, though not always, contain the word _should_ or _ought_; propositions of fact usually contain some form of the word _to be_. The following illustrations will make the distinction plainer:--

PROPOSITIONS OF POLICY.

The United States should adopt a system of bounties and subsidies for the protection of the American merchant marine.

State laws prohibiting secular employment on Sunday should be repealed.

A city furnishes a more desirable location for a college than the country.

The aggressions of England in Africa are justifiable.

PROPOSITIONS OF FACT.

Homer wrote the Iliad.

Nero was guilty of burning Rome.

Mary, Queen of Scots, murdered her husband.

The most convenient method of studying propositions to see what subjects are desirable for student debates is to consider first those propositions that should be avoided.

1. PROPOSITIONS WITH ONLY ONE SIDE. As argumentation presupposes a difference of opinion about a certain subject, evidently it is impossible to argue upon a subject on which all are agreed. Sometimes such propositions as, "_Resolved_, That Napoleon was a great soldier," and "_Resolved_, That railroads should take every precaution to protect the lives of their passengers," are found on the programs of literary societies and debating clubs. In such cases mere comment, not debate, can follow. Only subjects on which reasonable men actually disagree are suitable for argument.