Definition of Critical Thinking:  Reasonable reflective thinking focused on deciding what to believe or do.

A brief elaboration of the above definition, entitled “A Super-Streamlined Conception of Critical Thinking”, is below. For exemplification that includes the distinction between critical thinking dispositions and abilities, see “Critical Thinking: A Streamlined Conception” from Teaching Philosophy (1991).

For a longer, slightly-revised, un-exemplified definition/conception, see The Nature of Critical Thinking. This could serve as a comprehensive outline for a  critical thinking curriculum, or for the general aspects of “critical thinking across the curriculum”. It also could serve as the basis for a table of specifications for varying levels of critical thinking assessment. For considerably more elaboration and exemplification see Ennis’ Critical Thinking, published by Prentice Hall, 1996.


Developed (last revised 11/26/10) by Robert H. Ennis, A critical thinker:

1. Is open-minded and mindful of alternatives

2. Desires to be, and is, well-informed

3. Judges well the credibility of sources

4. Identifies reasons, assumptions, and conclusions

5. Asks appropriate clarifying questions

6. Judges well the quality of an argument, including its reasons, assumptions, evidence, and their degree of support for the conclusion

7. Can well develop and defend a reasonable position regarding a belief or an action, doing justice to challenges

8. Formulates plausible hypotheses

9. Plans and conducts experiments well

10. Defines terms in a way appropriate for the context

11. Draws conclusions when warranted – but with caution

12. Integrates all of the above aspects of critical thinking   Although the word ‘critical’ is sometimes used in a negative sense, this conception of critical thinking is not negative. Also, it does not treat critical thought as persuasion, but critical thought will, we hope, often be persuasive. The future of democracy depends on it.