How to Evaluate an Argument: Premises, Conclusions and Hidden Assumptions

To evaluate an argument, identify its conclusion and supporting premises, uncover any hidden assumptions, and test both the evidence and the reasoning connecting them. An argument can sound persuasive while resting on weak evidence or a missing step. Breaking it into parts makes those problems easier to see—and helps you decide what would strengthen it.

What is critical thinking?

Critical thinking is the careful evaluation of claims, reasons and evidence before reaching a judgment. In an argument, the conclusion is what the writer or speaker wants you to accept; the premises are the reasons offered in its support.

Words such as “therefore” and “so” can signal a conclusion, while “because” and “since” often introduce premises. They are clues, not rules: ask what claim the other statements are trying to establish.

For example: “The library should stay open later because many students have evening classes.” The proposed later hours are the conclusion; students having evening classes is the stated premise. A description or an unsupported opinion is not necessarily an argument.

What is analytical and critical thinking?

Analytical thinking breaks a problem into parts; critical thinking evaluates those parts and the conclusions drawn from them. Both are useful when you put an argument into standard form: list the premises first, then write the conclusion beneath them.

1. Premise: Many students have evening classes.
2. Hidden assumption: Later library hours would help enough of those students to justify keeping the library open.
3. Conclusion: The library should stay open later.

The hidden assumption is a plausible missing link, not necessarily something the speaker consciously believes. Ask whether later hours would address students’ needs and whether the benefit would justify the cost; the stated premise alone does not settle those questions. For more on breaking complex claims into parts, see analytical thinking explained.

What are good critical thinking skills?

Good argument analysis separates the reliability of the premises from the strength of the reasoning. A premise can be true and still offer too little support for the conclusion.

• Check evidence: How does the speaker know that many students have evening classes? A current enrollment report could help.
• Check relevance: Do those students need the library after its current closing time, or can they use it earlier?
• Consider alternatives: Online resources or different opening hours might meet the same need.
• Look for counterevidence: Low attendance during a trial of later hours could weaken the proposal, though the trial’s timing and publicity would also matter.

A deductively valid argument is one whose conclusion cannot be false if its premises are true; a sound deductive argument is valid and has true premises. An inductive argument aims for probable support rather than certainty, so evaluate its strength and the quality of its evidence. The library proposal is an inductive, practical argument: its conclusion remains open to competing evidence and considerations.

How to improve critical thinking skills?

Practice with an editorial, advertisement or everyday recommendation. Write its conclusion in one sentence, list its reasons, and add any assumption needed to connect the two. Then ask what evidence would change your mind and try to state the strongest reasonable objection.

Watch for hindsight bias: once an outcome is known, it can seem as though it was predictable all along. When evaluating a decision, distinguish the information available at the time from facts discovered later. Cognitive biases explained offers more ways to examine judgment.

Finally, revise your assessment in proportion to the evidence. You may find an argument convincing, reject it, or conclude that you need more information.

What does a critical thinking class teach?

A critical thinking class can teach argument structure, evidence evaluation, fallacies and the difference between inductive and deductive reasoning. Exercises may ask you to analyze claims in media, academic writing or everyday decisions.

The table summarizes the Humanities Critical Thinking & Analysis course from UPI Study.

Which colleges list Humanities Critical Thinking & Analysis on an equivalency chart?

These colleges show Humanities Critical Thinking & Analysis (HUM 201) on their equivalency charts with UPI Study. Open a college for its full chart.

See the rest of the equivalency on the Humanities Critical Thinking & Analysis course page, or open a college above for its full chart. ACE and NCCRS have over 2,100 cooperating colleges that will consider accepting credits; the final decision is with the universities.

Frequently Asked Questions about Critical Thinking

Final Thoughts on Critical Thinking

Choose an argument you have recently encountered and write out its conclusion, premises and one possible hidden assumption. Check the most important premise and ask whether another explanation could account for the evidence.