Critical thinking is the practice of examining a claim, an assumption, or a proposed course of action before accepting it, and doing so on stated grounds that another person can inspect and disagree with. It shows up as the questions a person asks before they start, the assumptions they write down rather than carry silently, the evidence they go and find when the available evidence is thin, and the willingness to change a position when what they find does not support it. It is a habit applied to one's own reasoning first and to other people's second.
What critical thinking is not
- It is not disagreement, and a person who objects to everything is not exercising it. It is not scepticism as a posture, which is disagreement with the effort removed. It is not being right: a carefully reasoned position that turns out to be wrong is a demonstration of the capability, and a correct answer arrived at by guessing is not. It is not the same as analysis, which is the examination of data; critical thinking is the examination of reasoning, including reasoning about data that is not there. And it is not caution. A person who declines to decide because the evidence is imperfect has avoided the judgement rather than exercised it.