Assumptions and Premises

Oftentimes arguments are based in part on beliefs without evidence. Sometimes these can be values that the writer assumes the reader holds in common with the writer. For instance, a writer persuading students to study may assume that students want to succeed and that success is defined as earning good grades. But if a student is in the class just to be near his girlfriend and doesn’t care whether he fails, the writer’s assumption is flawed (Barnet and Bedau 57).

Sometimes an assumption is stated as a premise. According to Yagelski, Miller, and Crouse-Powers, a good premise should be

1. general enough that an audience is likely to accept it, thus establishing a common ground between writer and audience.
2. specific enough to prepare the way for the argument that will follow.

Two premises joined to create an argument leading to a conclusion creates a syllogism.

Major Premise: All fathers are parents.
Minor Premise: John is a father.
Conclusion: Therefore, John is a parent.

If one of the premises is assumed or left unstated, the resulting argument is called an enthymeme.

Since Mabel is a mother, Mabel must also be a parent.

Works Cited

Barnet, Sylvia and Hugo Bedau. Critical Thinking, Reading, and Writing: A Critical Guide to Argument. 3rd ed. Boston: Bedford St. Martin's, 1999.

Yagelski, Robert P., Robert K. Miller, and Amy J. Crouse-Powers. The Informed Argument. 6th ed. Boston: Wadsworth, 2006.

ENGL1010 Composition I