Critical thinking consists of mental processes of discernment, analysis and evaluation. It includes possible processes of reflecting upon a tangible or intangible item in order to form a solid judgment that reconciles scientific evidence with common sense. In contemporary usage "critical" has a certain negative connotation that does not apply in the present case; the term "analytical thinking" may more accurately convey the idea.

Critical thinkers gather information from all senses, verbal and/or written expressions, reflection, observation, experience and reasoning. Critical thinking has its basis in intellectual criteria that go beyond subject-matter divisions and which include: clarity, credibility, accuracy, precision, relevance, depth, breadth, logic, significance and fairness.

Fundamentally, critical thinking is a form of judgment, specifically purposeful and reflective judgment. Using critical thinking one makes a decision or solves the problem of judging what to believe or what to do, but does so in a reflective way. That is by giving due consideration to the evidence, the context of judgement, the relevant criteria for making that judgment well, the applicable methods or techniques for forming that judgment, and the applicable theoretical and constructs for understanding the nature of the problem and the question at hand. These elements also happen to be the key defining characteristics of professional fields and academic disciplines. This is why critical thinking can occur within a given subject field (by reference to its specific set of permissible questions, evidence sources, criteria, etc.) and across subject fields in all those spaces where human beings need to interact and make decisions, solve problems, and figure out what to believe and what to do. A useful, brief, and higly readable explanation of the concept of critical thinking, its skills and dispositional dimensions, its relationship to cognitive science, and its practical value in life and learning can be found in the free on-line resource: "Critical Thinking: What It is and Why It Counts"

Within the framework of scientific 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. However, a large part of critical thinking goes beyond informal logic and includes assessment of beliefs and identification of prejudice, bias, propaganda, self-deception, distortion, misinformation, etc. Given research in cognitive psychology, some educators believe that schools should focus more on teaching their students critical thinking skills, intellectual standards, and cultivating intellectual traits (such as intellectual humility, intellectual empathy, intellectual integrity, and fair-mindedness) than on memorizing facts by rote learning. As defined in A Greek-English Lexicon the verb krino- means to choose, decide or judge. Hence a krites is a discerner, judge or arbiter. Those who are kritikos have the ability to discern or decide.

The word krino- also means to separate (winnow) the wheat from the chaff or that which has worth from that which does not.

Critical thinking is a pervasive human process, evident in children and adults. It is important, because it enables one to analyze, evaluate, explain, and restructure our thinking, decreasing thereby the risk of acting on, or thinking with, a false premise.

However, even with the use of critical thinking skills, mistakes can happen due to a thinker's egocentrism or sociocentrism or failure to be in possession of the full facts. In addition, there is always the possibility of inadvertent human error.

Universal concepts and principles of critical thinking can be applied to any context or case but only by reflecting upon the nature of that application. Critical thinking forms, therefore, a system of related, and overlapping, modes of thought such as anthropological thinking, sociological thinking, historical thinking, political thinking, psychological thinking, philosophical thinking, mathematical thinking, chemical thinking, biological thinking, ecological thinking, legal thinking, ethical thinking, musical thinking, thinking like a painter, sculptor, engineer, business person, etc. In other words, though critical thinking principles are universal, their application to disciplines requires a process of reflective contextualization.

One can regard critical thinking as involving two aspects:

1. a set of cognitive skills, intellectual standards, and traits of mind
2. the disposition or intellectual commitment to use those structures to improve thinking and 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.

What is and is not universal in critical thinking

Critical thinking is based on concepts and principles, not on hard and fast, or step-by-step, procedures.

Critical thinking does not assure that one will reach either the truth or correct conclusions. First, one may not have all the relevant information; indeed, important information may remain undiscovered, or the information may not even be knowable. Furthermore, one may make unjustified inferences, use inappropriate concepts, fail to notice important implications, use a narrow or unfair point of view. One may be a victim of self-delusion, egocentricity or sociocentricity, or closed-mindedness. One's thinking may be unclear, inaccurate, imprecise, irrelevant, narrow, shallow, illogical, or trivial. One may be intellectually arrogant, intellectually lazy, or intellectually hypocritical. These are some of the ways that human thinking can be flawed. Further information can be found in the Thinker's Guide series by Richard Paul and Linda Elder.

Human thinking left to itself often leads to various forms of self-deception, individually and socially; and at the left, right, and mainstream of economic, political, and religious issues. Further analysis and resources about this interaction may be found in Roderick Hindery (2001): Indoctrination and Self-deception or Free and Critical Thought.

The uses of critical thinking

Critical thinking is useful only in those situations where human beings need to solve problems, make decisions, or decide in a reasonable and reflective way what to believe or what to do.(Robert Ennis) That is, just about everywhere and all the time. Critical thinking is important wherever the quality of human thinking significantly impacts the quality of life (of any sentient creature). For example, success in human life is tied to success in learning. At the same time, every phase in the learning process is tied to critical thinking. Thus, reading, writing, speaking, and listening can all be done critically or uncritically. Critical thinking is crucial to becoming a close reader and a substantive writer. Expressed most generally, critical thinking is “a way of taking up the problems of life.” (William Graham Sumner, Folkways, 1906)

Irrespective of the sphere of thought, “a well cultivated critical thinker":

• raises vital questions and problems, formulating them clearly and precisely;
• gathers and assesses relevant information, using abstract ideas to interpret it effectively
• comes to well-reasoned conclusions and solutions, testing them against relevant criteria and standards;
• thinks open-mindedly within alternative systems of thought, recognizing and assessing, as need be, their assumptions, implications, and practical consequences; and
• communicates effectively with others in figuring out solutions to complex problems.

(Paul, R. and Elder, 2006)

The affective dimension of critical thinking

Critical thinking is about being both willing and able to think. Ideally one develops critical thinking skills and at the same time the disposition to use those skills to solve problems and form good judgments. The dispositional dimension of critical thinking is characterological. Its focus in developing the habitual intention to be truth-seeking, open-minded, systematic, analytical, inquisitive, confident in reasoning, and prudent in making judgments. Those who are ambivalent on one or more of these aspects of the disposition toward critical thinking, or who have the opposite disposition [biased, intolerant, disorganized, heedless of consequences, indifferent toward new information, mistrustful of reasoning, imprudence]are less likely to engage problems using their critical thinking skills. The relationship between critical thinking skills and critical thinking dispositions is an empirical question. Some have both in abundance, some have skills but not the disposition to use them, some are disposed but lack strong skills and some have neither. Two measures of critical thinking dispositions are the California Critical Thinking Disposition Inventory [2]and the CM3 [3].

Critical thinking may be distinguished, but not separated, from emotions, desires, and traits of mind. Failure to recognize the relationship between thinking, feeling, wanting, and traits of mind can easily lead to various forms of self-deception, both individually and collectively. When persons possess intellectual skills alone, without the intellectual traits of mind, weak sense critical thinking results. Fair-minded or strong sense critical thinking requires intellectual humility, empathy, integrity, perseverance, courage, autonomy, confidence in reason, and other intellectual traits. Thus, critical thinking without essential intellectual traits often results in clever, but manipulative, often unethical, thought. In short, the sophist, the con artist, the manipulator often uses an intellectually defective but effective form of thought---serving unethical purposes. However, whereas critical thinking yields itself to analytical consideration readily and may be considered largely "objective", the notions of socially-based mores and taboos are largely relative and "subjective".

Further analysis and resources about the interaction between thought, desires, and emotions may be found in Roderick Hindery (2001): Indoctrination and Self-deception or Free and Critical Thought and in Paul and Elder (2004): The Human Mind.

Overcoming bias

There is no simple way to reduce one's bias. There are, however, ways that one can begin to do so. The most important require developing one's intellectual empathy and intellectual humility. The first requires extensive experience in entering and accurately constructing points of view toward which one has negative feelings. The second requires extensive experience in identifying the extent of one's own ignorance in a wide variety of subjects (ignorance whose admission leads one to say, "I thought I knew, but I merely believed"). One becomes less biased and more broad-minded when one becomes more intellectually empathic and intellectually humble, and that involves time, deliberate practice and commitment. It involves considerable personal and intellectual development.

To develop one's critical thinking abilities, one should learn the art of suspending judgment (for example, when reading a novel, watching a movie, engaging in dialogical or dialectical reasoning). 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.

One should become aware of one's own fallibility by:

1. accepting that everyone has subconscious biases, and accordingly questioning any reflexive judgments.
2. adopting an ego-sensitive and, indeed, intellectually humble stance
3. recalling previous beliefs that one once held strongly but now rejects
4. realizing one still has numerous blind spots, despite the foregoing

An integration of insights from the critical thinking literature and cognitive psychology literature is the "Method of Argument and Heuristic Analysis." This technique illustrates the influeces of heuristics and biases on human decision making along with the influences of thinking critically about reasons and claims. Thinking and Reasoning in Human Decision Making [4]

Critical thinking in the classroom

The key to seeing the significance of critical thinking in the classroom is in understanding the significance of critical thinking in learning. To learn is to think. To think poorly is to learn poorly. To think well is to learn well. All content, to be learned, must be intellectually constructed. To learn the content of history, I must engage myself in the process of thinking historically.

There are two phases to the learning of content. The first occurs when learners (for the first time) construct in their minds the basic ideas, principles, theories that are inherent in content. This is a process of internalization. The second occurs when learners effectively use those ideas, principles, and theories as they become relevant in learners’ lives. This is a process of application. Good teachers cultivate critical thinking (intellectually engaged thinking) at every stage of learning, including initial learning. This process of intellectual engagement is at the heart of the Oxford and Cambridge tutorials. The tutor questions the students, often in a Socratic manner. Here are some typical Socratic questions:

• What do you mean by_______________?
• How did you come to that conclusion?
• What was said in the text?
• What is the source of your information?
• What is the source of information in the report?
• What assumption has led you to that conclusion?
• Suppose you are wrong. What are the implications?
• Why did you make that inference? Is another one more consistent with the data?
• Why is this issue significant?
• How do I know that what you are saying is true?
• What is an alternate explanation for this phenomenon?

Of course, there are many other possible Socratic questions. The key is that the teacher who fosters critical thinking fosters reflectiveness in students by asking questions that stimulate thinking essential to the construction of knowledge.

As emphasized above, each discipline adapts its use of critical thinking concepts and principles. The core concepts are always there, but they are embedded in subject specific content. For students to learn content, intellectual engagement is crucial. All students must do their own thinking, their own construction of knowledge. Good teachers recognize this and therefore focus on the questions, readings, activities that stimulate the mind to take ownership of key concepts and principles underlying the subject.

In the UK school system, the syllabus offers Critical thinking as a subject which 16-18 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". The exam tests candidates not on particular information they have learned during the course, but on their ability to think critically about, and analyze, arguments on their deductive or inductive validity. The full advanced GCE is now available and, though very challenging, is extremely useful for degree courses in politics, philosophy, history or theology (to name but a few), providing the skills required for critical analysis that are useful, for example, in biblical study.

Measuring or Assessing Critical Thinking

Several well-researched tools are available to measure critical thinking skills and critical thinking dispositions. Some are designed for younger students, others for college students and adults. While most are developed for use in a general education or every day context, some are tailored for the interests of people in different professional fields. In addition to tests, other tools for assessing critical thinking include rubrics and performance rating forms. For examples and more detailed discussion, and for free materials including the Holisitic Critical Thinking Scoring Rubric, visit Insight Assessment.

Reaching a conclusion

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.

Quotations

William Graham Sumner offers a useful summary of critical thinking:

The critical habit of thought, if usual in society, will pervade all its mores, because it is a way of taking up the problems of life. Men educated in it cannot be stampeded by stump orators ... They are slow to believe. They can hold things as possible or probable in all degrees, without certainty and without pain. They can wait for evidence and weigh evidence, uninfluenced by the emphasis or confidence with which assertions are made on one side or the other. They can resist appeals to their dearest prejudices and all kinds of cajolery. Education in the critical faculty is the only education of which it can be truly said that it makes good citizens.

Martin Luther King said:

The function of education, therefore, is to teach one to think intensively and to think critically . . . The complete education gives one not only power of concentration but worthy objectives upon which to concentrate.