Within the framework of skepticism, the process of critical thinking involves acquiring information and evaluating it to reach a well-justified conclusion or answer. Part of critical thinking comprises informal logic. Given research in cognitive psychology, educators increasingly believe that schools should focus more on teaching their students critical thinking skills than on memorizing facts by rote-learning.
The process of critical thinking responds to many subjects and situations, finding connections between them. It forms, therefore, a system of related modes of thought that cut across fields like science, mathematics, engineering, history, anthropology, economics, moral reasoning and philosophy.
One can regard critical thinking as involving two aspects:
- a set of cognitive skills
- the ability and intellectual commitment to use those skills to guide behavior.
Critical thinking does not include simply the acquisition and retention of information, or the possession of a skill-set which one does not use regularly; nor does critical thinking merely exercise skills without acceptance of the results.
Methods of critical thinking
Critical thinking has a useful sequence to follow:
- Itemize opinion(s) from all relevant sides of an issue and collect Logical argument(s) supporting each.
- Break the arguments into their constituent statements and draw out various additional implication(s) from these statements.
- Examine these statements and implications for internal contradictions.
- Locate opposing claims between the various arguments and assign relative weightings to opposing claims.
- Increase the weighting when the claims have strong support especially distinct chains of reasoning or different news sources, decrease the weighting when the claims have contradictions.
- Adjust weighting depending on relevance of information to central issue.
- Require sufficient support to justify any incredible claims; otherwise, ignore these claims when forming a judgment.
- Assess the weights of the various claims.
Mind maps provide an effective tool for organizing and evaluating this information; in the final stages, one can assign numeric weights to various branches of the mind map.
Critical thinking does not assure that one will reach either the truth or correct conclusions. Firstly, one may not have all the relevant information; indeed, important information may remain undiscovered, or the information may not even be knowable. Second, one's bias(es) may prevent effective gathering and evaluation of the available information.
To reduce one's bias, one can take various measures during the process of critical thinking.
Instead of asking "How does this contradict my beliefs?" ask: "What does this mean?"
In the earlier stages of gathering and evaluating information, one should first of all suspend judgement (as one does when reading a novel or watching a movie). Ways of doing this include adopting a perceptive rather than judgmental orientation; that is, avoiding moving from perception to judgment as one applies critical thinking to an issue. In the terminology of Edward De Bono's Six Thinking Hats, use white hat or blue hat thinking and delay black hat thinking for later stages.
One should become aware of one's own fallibility by:
- accepting that everyone has subconscious biases, and accordingly questioning any reflexive judgments;
- adopting an egoless and, indeed, humble stance
- recalling previous beliefs that one once held strongly but now rejects
- realizing one still has numerous blind spots, despite the foregoing
How does one ever eliminate biases without knowing what the ideal is? A possible answer: by referencing critical thinking against a "concept of man" (see Erich Fromm). Thus we can see that critical thinking and the formation of secure ethical codes form an integral whole, but a whole which remains limited without the backing of a concept of humanity.
Finally, one might use the Socratic method to evaluate an argument, asking open questions, such as the following:
- What do you mean by_______________?
- How did you come to that conclusion?
- Why do you believe that you are right?
- What is the source of your information?
- What happens if you are wrong?
- Can you give me two sources who disagree with you and explain why?
- Why is this significant?
- How do I know you are telling me the truth?
- What is an alternate explanation for this phenomenon?
Reaching a conclusion
One useful perspective in critical thinking involves Occam's Razor. Also called the "principle of parsimony," Occam's razor states that one should not make more assumptions than necessary. In other words, "keep it simple". Given the nature of the process, critical thinking is never final. One arrives at a tentative conclusion, given the evidence and based on an evaluation. However, the conclusion must always remain subject to further evaluation if new information comes to hand.
Critical thinking in the classroom
In the UK school system, the syllabus offers Critical thinking as a subject which 17-18 year olds can take as an A-Level. Under the OCR exam board, students can sit two exam papers: "Credibility of Evidence" and "Assessing/Developing Argument". Students often regard the subject as a 'lightweight' or 'bonus' qualification, as they can achieve competence after very little formal teaching.
William Graham Sumner offers a useful summary of critical thinking:
- Critical thinking is the examination and test of propositions of any kind which are offered for acceptance, in order to find out whether they correspond to reality or not. The critical faculty is a product of education and training. It is a mental habit and power. It is a prime condition of human welfare that men and women should be trained in it. It is our only guarantee against delusion, deception, superstition, and misapprehension of ourselves and our earthly circumstances.
- Paul, R. and Elder L. 2002. Critical Thinking: Tools for Taking Charge of Your Professional and Personal Life. Published by Financial Times Prentice Hall. ISBN 0-13-064760-8.
- Paul, R., Elder, L., and Bartell T. 1997. California Teacher Preparation for Instruction in Critical Thinking: Research Findings and Policy Recommendations. California Commission on Teacher Credentialing. Foundation for Critical Thinking, Sacramento California.
- Whyte, P. 2003. Bad Thoughts - A Guide to Clear Thinking. Published by Corvo. ISBN 0-9543255-3-2.