Recognising Assumptions guide
Recognising Assumptions questions ask which unstated claim the argument depends on. An assumption is a required bridge between the premises and the conclusion — not just any related true fact.
The method
- Apply the negation test: negate the candidate assumption.
- If the argument falls apart once the candidate is false, it was a required assumption.
- If the argument survives the negation, the candidate was not assumed — even if it's true.
- Look for definitional and enabling bridges the conclusion silently relies on.
Common mistakes
- Treating 'it's true' as 'it's assumed'.
- Confusing a supporting fact with a required bridge.
- Missing a definitional assumption the conclusion depends on.
- Choosing a claim that strengthens the argument but isn't necessary to it.
Frequently asked questions
Why does the negation test work?
A genuine assumption is load-bearing: deny it and the conclusion no longer follows. If denying it leaves the argument standing, it was never assumed.