Knowledge you can walk. Read the idea below, then step up to the general, across to peers or down to the specific.
Mental
Identifying Assumptions
Identifying assumptions means finding the unstated ideas an argument or decision takes for granted, a core skill of critical thinking.
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The idea
Identifying assumptions means finding the ideas that an argument, decision or judgment takes for granted without saying them. Many assumptions are tacit, or implicit. They are not spoken aloud, and the person relying on them may not even notice them. Such assumptions often grow out of personal life experience.
Arguments often leave a premise unstated. An argument with a hidden premise is called an enthymeme. For example, someone might say, "We should leave early, because it might snow." The hidden premise is that snow slows down travel. Enthymemes usually rest on premises that the audience already treats as common sense. Those premises are often only probable, so the conclusion is only tentative.
Hidden assumptions matter because they can cause misunderstandings, apparent paradoxes and resistance to change. Two people may argue for a long time without noticing that they start from different unstated beliefs. Even science rests on tacit assumptions, such as the elegance of natural laws and the usefulness of mathematics for describing the world. A good way to find an assumption is to ask what else would have to be true for the conclusion to follow.
Check yourself
Question 1 of 2
What is an argument with a hidden premise called?
Composition
what it's made of
- Stated premises — The reasons an argument openly gives.
- Hidden premises — Unstated reasons an argument needs, as in an enthymeme.
- Tacit assumptions — Beliefs behind a decision or judgment that are never voiced and may go unnoticed.
- Probing questions — Asking what else must be true for the conclusion to follow.
Connection
how it relates
Under Evaluating Evidence
Change
how and why it evolves
- Past
- Aristotle first theorized the enthymeme and described it as "the strongest of rhetorical proofs." Much later, in 1815, the exact term critical thinking first appeared, in the British literary journal The Critical Review.
- Now
- Today recognizing underlying assumptions is taught as a core part of critical thinking, a skill that can be learned and trained.
- Next
- As more information arrives in short posts and ads, the habit of asking what a message takes for granted will likely become even more useful.