In Composition you learned what makes a thesis strong: specific, clear, and arguable. An argument’s thesis is a claim, usually of value or policy, and AP English Language calls the goal a defensible thesis.
Key idea
A defensible thesis takes a position that reasonable people could dispute, and that you can defend with evidence and reasoning.
Why it works
If no one could disagree, there is nothing to argue; the essay becomes a report. If no evidence could support it, the essay becomes a list of opinions. A defensible thesis sits between the two: open to dispute, and open to proof.
| Not yet defensible | Why | Defensible |
|---|---|---|
| The library is open until 4:00. | a fact: no one disputes it | The library should stay open until 6:00 during exam weeks. |
| I like rainy days better than sunny ones. | a pure preference: no evidence could change it | Our school should hold recess indoors only during heavy rain or extreme cold. |
| This essay will discuss school start times. | an announcement, not a claim | Starting high school at 8:30 would help students more than it would cost the district. |
| Technology affects society in many ways. | too broad and vague to argue | Requiring phones to stay in lockers during class would help students in our school focus. |
Worked example: Revise toward defensible
Draft thesis: “Recess is a part of the school day.” Make it defensible.
- The draft is a fact; no one disputes it.
- Ask what people do dispute about recess: its length, whether it can be taken away, when it happens.
- Choose one and take a side you can support: “Elementary schools should not take away recess as a punishment, because…”
Answer: “Elementary schools should not take away recess as a punishment, because movement helps children focus and other consequences work as well.”
Common mistake
Writing a thesis no one would dispute (a fact) or one no evidence could support (a pure preference). Check with two questions: Could a thoughtful person disagree? Could I show evidence that would move them? You need two yeses.
For practice topics with both sides laid out, see the Debate topic pages, such as Taking Away Recess and Later School Start Times.