Critical thinking

Critical thinking is the analysis of available facts, evidence, observations, and arguments in order to form a judgement by the application of rational, skeptical, and unbiased analyses and evaluation.^[1] In modern times, the use of the phrase critical thinking can be traced to John Dewey, who used the phrase reflective thinking.^[2] The application of critical thinking includes self-directed, self-disciplined, self-monitored, and self-corrective habits of the mind;^[3] thus, a critical thinker is a person who practices the skills of critical thinking or has been trained and educated in its disciplines.^[4] Philosopher Richard W. Paul said that the mind of a critical thinker engages the person's intellectual abilities and personality traits.^[5] Critical thinking presupposes assent to rigorous standards of excellence and mindful command of their use in effective communication and problem solving, and a commitment to overcome egocentrism and sociocentrism.^[6][7]

In the classical period (5th c.–4th c. BC) of Ancient Greece, the philosopher Plato (428–347 BC) indicated that the teachings of Socrates (470–399 BC) are the earliest records of what today is called critical thinking. In an early dialogue by Plato, the philosopher Socrates debates several speakers about the ethical matter of the rightness or wrongness of Socrates escaping from prison.^[8] Upon consideration, Plato concluded that to escape prison would violate everything he believes to be greater than himself: the laws of Athens and the guiding voice that Socrates claims to hear.^[8]

Socrates established the unreliability of Authority and of authority figures to possess knowledge and consequent insight; that for an individual man or woman to lead a good life that is worth living, that person must ask critical questions and possess an interrogative soul,^[9] which seeks evidence and then closely examines the available facts, and then follows the implications of the statement under analysis, thereby tracing the implications of thought and action.^[10]

As a form of co-operative argumentation, Socratic questioning requires the comparative judgment of facts, which answers then would reveal the person's irrational thinking and lack of verifiable knowledge. Socrates also demonstrated that Authority does not ensure accurate, verifiable knowledge; thus, Socratic questioning analyses beliefs, assumptions, and presumptions, by relying upon evidence and a sound rationale.^[11]

In modern times, the phrase critical thinking was coined by Pragmatist philosopher John Dewey in his book How We Think.^[12] As a type of intellectualism, the development of critical thinking^[13] is a means of critical analysis that applies rationality to develop a critique of the subject matter.^[14] According to the Foundation for Critical Thinking,^[15] in 1987 the U.S. National Council for Excellence in Critical Thinking defined critical thinking as the "intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action."^[16]

In the term critical thinking, the word critical, (Grk. κριτικός = kritikos = "critic") derives from the word critic and implies a critique; it identifies the intellectual capacity and the means "of judging", "of judgement", "for judging", and of being "able to discern".^[17] The intellectual roots of critical^[18] thinking are as ancient as its etymology, traceable, ultimately, to the critical reasoning of the Presocractic philosophers,^[19] as well as the teaching practice and vision of Socrates^[20] 2,500 years ago who discovered by a method of probing questioning that people could not rationally justify their confident claims to knowledge.

According to the Oxford English Dictionary, the exact term “critical thinking” first appeared in 1815, in the British literary journal The Critical Review, referring to critical analysis in the literary context. The meaning of "critical thinking" gradually evolved and expanded to mean a desirable general thinking skill by the end of the 19th century and early 20th century.^[19]

Traditionally, critical thinking has been variously defined as follows:

• "The intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action."^[21]
• "Disciplined thinking that is clear, rational, open-minded, and informed by evidence"^[22]
• "Purposeful, self-regulatory judgment which results in interpretation, analysis, evaluation, and inference, as well as explanation of the evidential, conceptual, methodological, criteriological, or contextual considerations upon which that judgment is based"^[23]
• "Includes a commitment to using reason in the formulation of our beliefs"^[24]
• The skill and propensity to engage in an activity with reflective scepticism (McPeck, 1981)^[25]
• Thinking about one's thinking in a manner designed to organize and clarify, raise the efficiency of, and recognize errors and biases in one's own thinking. Critical thinking is not 'hard' thinking nor is it directed at solving problems (other than 'improving' one's own thinking). Critical thinking is inward-directed with the intent of maximizing the rationality of the thinker. One does not use critical thinking to solve problems—one uses critical thinking to improve one's process of thinking.^[26]
• "An appraisal based on careful analytical evaluation"^[27]
• "Critical thinking is a type of thinking pattern that requires people to be reflective, and pay attention to decision-making which guides their beliefs and actions. Critical thinking allows people to deduct with more logic, to process sophisticated information and look at various sides of an issue so they can produce more solid conclusions."^[28]
• Critical thinking has seven critical features: being inquisitive and curious, being open-minded to different sides, being able to think systematically, being analytical, being persistent to truth, being confident about critical thinking itself, and lastly, being mature.^[29]
• Although critical thinking could be defined in several different ways, there is a general agreement in its key component—the desire to reach for a satisfactory result, and this should be achieved by rational thinking and result-driven manner. Halpern thinks that critical thinking firstly involves learned abilities such as problem-solving, calculation and successful probability application. It also includes a tendency to engage the thinking process. In recent times, Stanovich believed that modern IQ testing could hardly measure the ability of critical thinking.^[30]
• "Critical thinking is essentially a questioning, challenging approach to knowledge and perceived wisdom. It involves ideas and information from an objective position and then questioning this information in the light of our own values, attitudes and personal philosophy."^[31]

Contemporary critical thinking scholars have expanded these traditional definitions to include qualities, concepts, and processes such as creativity, imagination, discovery, reflection, empathy, connecting knowing, feminist theory, subjectivity, ambiguity, and inconclusiveness. Some definitions of critical thinking exclude these subjective practices.^[32][21]

1. According to Ennis, "Critical thinking is the intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action."^[33] This definition Ennis provided is highly agreed by Harvey Siegel,^[34] Peter Facione,^[29] and Deanna Kuhn.^[35]
2. According to Ennis' definition, critical thinking requires a lot of attention and brain function. When a critical thinking approach is applied to education, it helps the student's brain function better and understand texts differently.
3. Different fields of study may require different types of critical thinking. Critical thinking provides more angles and perspectives upon the same material.

The study of logical argumentation is relevant to the study of critical thinking. Logic is concerned with the analysis of arguments, including the appraisal of their correctness or incorrectness.^[36] In the field of epistemology, critical thinking is considered to be logically correct thinking, which allows for differentiation between logically true and logically false statements.^[37]

In "First wave" logical thinking, the thinker is removed from the train of thought, and the analysis of connections between concepts or points in thought is ostensibly free of any bias. In his essay Beyond Logicism in Critical Thinking Kerry S. Walters describes this ideology thus: "A logistic approach to critical thinking conveys the message to students that thinking is legitimate only when it conforms to the procedures of informal (and, to a lesser extent, formal) logic and that the good thinker necessarily aims for styles of examination and appraisal that are analytical, abstract, universal, and objective. This model of thinking has become so entrenched in conventional academic wisdom that many educators accept it as canon".^[32] Such principles are concomitant with the increasing dependence on a quantitative understanding of the world.^{[citation needed]}

In the 'second wave' of critical thinking, authors consciously moved away from the logocentric mode of critical thinking characteristic of the 'first wave'. Although many scholars began to take a less exclusive view of what constitutes critical thinking, rationality and logic remain widely accepted as essential bases for critical thinking. Walters argues that exclusive logicism in the first wave sense is based on "the unwarranted assumption that good thinking is reducible to logical thinking".^[32]

There are three types of logical reasoning. Informally, two kinds of logical reasoning can be distinguished in addition to formal deduction, which are induction and abduction.

• Deduction is the conclusion drawn from the structure of an argument's premises, by use of rules of inference formally those of propositional calculus. For example: X is human and all humans have a face, so X has a face.

• Induction is drawing a conclusion from a pattern that is guaranteed by the strictness of the structure to which it applies. For example: The sum of even integers is even. Let ${\displaystyle x,y,z\in \mathbb {Z} }$ then ${\displaystyle 2x,2y,2z}$ are even by definition. If ${\displaystyle x+y=z}$, then ${\displaystyle 2x+2y=2(x+y)=2z}$, which is even; so summing two even numbers results in an even number.

• Abduction is drawing a conclusion using a heuristic that is likely, but not inevitable given some foreknowledge. For example: I observe sheep in a field, and they appear white from my viewing angle, so sheep are white. Contrast with the deductive statement: Some sheep are white on at least one side.

Kerry S. Walters, an emeritus philosophy professor from Gettysburg College, argues that rationality demands more than just logical or traditional methods of problem solving and analysis or what he calls the "calculus of justification" but also considers "cognitive acts such as imagination, conceptual creativity, intuition and insight".^[32]: 63 These "functions" are focused on discovery, on more abstract processes instead of linear, rules-based approaches to problem-solving. The linear and non-sequential mind must both be engaged in the rational mind.^[32]

The ability to critically analyze an argument — to dissect structure and components, thesis and reasons — is essential. But so is the ability to be flexible and consider non-traditional alternatives and perspectives. These complementary functions are what allow for critical thinking to be a practice encompassing imagination and intuition in cooperation with traditional modes of deductive inquiry.^[32]

The list of core critical thinking skills includes observation, interpretation, analysis, inference, evaluation, explanation, and metacognition. According to Reynolds (2011), an individual or group engaged in a strong way of critical thinking gives due consideration to establish for instance:^[38]

• Evidence through reality
• Context skills to isolate the problem from context
• Relevant criteria for making the judgment well
• Applicable methods or techniques for forming the judgment
• Applicable theoretical constructs for understanding the problem and the question at hand

In addition to possessing strong critical-thinking skills, one must be disposed to engage problems and decisions using those skills. Critical thinking employs not only logic but broad intellectual criteria such as clarity, credibility, accuracy, precision, relevance, depth, breadth, significance, and fairness.^[39]

Critical thinking calls for the ability to:

• Recognize problems, to find workable means for meeting those problems
• Understand the importance of prioritization and order of precedence in problem-solving
• Gather and marshal pertinent (relevant) information
• Recognize unstated assumptions and values
• Comprehend and use language with accuracy, clarity, and discernment
• Interpret data, to appraise evidence and evaluate arguments
• Recognize the existence (or non-existence) of logical relationships between propositions
• Draw warranted conclusions and generalizations
• Put to test the conclusions and generalizations at which one arrives
• Reconstruct one's patterns of beliefs on the basis of wider experience
• Render accurate judgments about specific things and qualities in everyday life

In sum:

"A persistent effort to examine any belief or supposed form of knowledge in the light of the evidence that supports or refutes it and the further conclusions to which it tends."^[40]

The habits of mind that characterize a person strongly disposed toward critical thinking include a desire to follow reason and evidence wherever they may lead, a systematic approach to problem-solving, inquisitiveness, even-handedness, and confidence in reasoning.^[41]

According to a definition analysis by Kompf & Bond (2001), critical thinking involves problem-solving, decision making, metacognition,^[42] rationality, rational thinking, reasoning, knowledge, intelligence and also a moral component such as reflective thinking. Critical thinkers therefore need to have reached a level of maturity in their development, possess a certain attitude as well as a set of taught skills.

There is a postulation by some writers that the tendencies from habits of mind should be thought as virtues to demonstrate the characteristics of a critical thinker.^[43] These intellectual virtues are ethical qualities that encourage motivation to think in particular ways towards specific circumstances. However, these virtues have also been criticized by skeptics who argue that the evidence is lacking for a specific mental basis underpinning critical thinking.^[44]

After undertaking research in schools, Edward M. Glaser proposed in 1941 that the ability to think critically involves three elements:^[40]

1. An attitude of being disposed to consider in a thoughtful way the problems and subjects that come within the range of one's experiences
2. Knowledge of the methods of logical inquiry and reasoning
3. Some skill in applying those methods.^[40]

Educational programs aimed at developing critical thinking in children and adult learners, individually or in group problem solving and decision making contexts, continue to address these same three central elements.

The Critical Thinking project at Human Science Lab, London, is involved in the scientific study of all major educational systems in prevalence today to assess how the systems are working to promote or impede critical thinking.^[45]

Contemporary cognitive psychology regards human reasoning as a complex process that is both reactive and reflective.^[46] This presents a problem that is detailed as a division of a critical mind in juxtaposition to sensory data and memory.

The psychological theory disposes of the absolute nature of the rational mind, in reference to conditions, abstract problems and discursive limitations. Where the relationship between critical-thinking skills and critical-thinking dispositions is an empirical question, the ability to attain causal domination exists, for which Socrates was known to be largely disposed against as the practice of Sophistry. Accounting for a measure of "critical-thinking dispositions" is the California Measure of Mental Motivation^[47] and the California Critical Thinking Dispositions Inventory.^[48] The Critical Thinking Toolkit is an alternative measure that examines student beliefs and attitudes about critical thinking.^[49]

John Dewey is one of many educational leaders who recognized that a curriculum aimed at building thinking skills would benefit the individual learner, the community, and the entire democracy.^[50]

Critical thinking is significant in the learning process of internalization, in the construction of basic ideas, principles, and theories inherent in content. And critical thinking is significant in the learning process of application, whereby those ideas, principles, and theories are implemented effectively as they become relevant in learners' lives.^{[citation needed]}

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.^{[citation needed]} 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.^{[citation needed]}

Historically, the teaching of critical thinking focused only on logical procedures such as formal and informal logic.^{[citation needed]} This emphasized to students that good thinking is equivalent to logical thinking. However, a second wave of critical thinking, urges educators to value conventional techniques, meanwhile expanding what it means to be a critical thinker. In 1994, Kerry Walters^[32] compiled a conglomeration of sources surpassing this logical restriction to include many different authors' research regarding connected knowing, empathy, gender-sensitive ideals, collaboration, world views, intellectual autonomy, morality and enlightenment. These concepts invite students to incorporate their own perspectives and experiences into their thinking.

In the English and Welsh school systems, Critical Thinking is offered as a subject that 16- to 18-year-olds can take as an A-Level. Under the OCR exam board, students can sit two exam papers for the AS: "Credibility of Evidence" and "Assessing and Developing Argument". The full Advanced GCE is now available: in addition to the two AS units, candidates sit the two papers "Resolution of Dilemmas" and "Critical Reasoning". The A-level tests candidates on their ability to think critically about, and analyze, arguments on their deductive or inductive validity, as well as producing their own arguments. It also tests their ability to analyze certain related topics such as credibility and ethical decision-making. However, due to its comparative lack of subject content, many universities do not accept it as a main A-level for admissions.^[51] Nevertheless, the AS is often useful in developing reasoning skills, and the full Advanced GCE is useful for degree courses in politics, philosophy, history or theology, providing the skills required for critical analysis that are useful, for example, in biblical study.

There used to also be an Advanced Extension Award offered in Critical Thinking in the UK, open to any A-level student regardless of whether they have the Critical Thinking A-level. Cambridge International Examinations have an A-level in Thinking Skills.^[52]

From 2008, Assessment and Qualifications Alliance has also been offering an A-level Critical Thinking specification.^[53] OCR exam board have also modified theirs for 2008. Many examinations for university entrance set by universities, on top of A-level examinations, also include a critical-thinking component, such as the LNAT, the UKCAT, the BioMedical Admissions Test and the Thinking Skills Assessment.

In Qatar, critical thinking was offered by Al-Bairaq - an outreach, non-traditional educational program that targeted high school students and focussed on a curriculum based on STEM fields. The idea behind this was to offer high school students the opportunity to connect with the research environment in the Center for Advanced Materials (CAM) at Qatar University. Faculty members train and mentor the students and help develop and enhance their critical thinking, problem-solving, and teamwork skills.^{[54][failed verification]}

In 1995, a meta-analysis of the literature on teaching effectiveness in higher education was undertaken.^[55] The study noted concerns from higher education, politicians, and business that higher education was failing to meet society's requirements for well-educated citizens. It concluded that although faculty may aspire to develop students' thinking skills, in practice they have tended to aim at facts and concepts utilizing lowest levels of cognition, rather than developing intellect or values.

In a more recent meta-analysis, researchers reviewed 341 quasi- or true-experimental studies, all of which used some form of standardized critical-thinking measure to assess the outcome variable.^[56] The authors describe the various methodological approaches and attempt to categorize differing assessment tools, which include standardized tests (and second-source measures), tests developed by teachers, tests developed by researchers, and tests developed by teachers who also serve the role as the researcher. The results emphasized the need for exposing students to real-world problems and the importance of encouraging open dialogue within a supportive environment. Effective strategies for teaching critical thinking are thought to be possible in a wide variety of educational settings.^[56] One attempt to assess the humanities' role in teaching critical thinking and reducing belief in pseudoscientific claims was made at North Carolina State University. Some success was noted and the researchers emphasized the value of the humanities in providing the skills to evaluate current events and qualitative data in context.^[57]

Scott Lilienfeld notes that there is some evidence to suggest that basic critical-thinking skills might be successfully taught to children at a younger age than previously thought.^[58]

Critical thinking is an important element of all professional fields and academic disciplines (by referencing their respective sets of permissible questions, evidence sources, criteria, etc.). Within the framework of scientific skepticism, the process of critical thinking involves the careful acquisition and interpretation of information and use of it to reach a well-justified conclusion. The 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. Psychology offerings, for example, have included courses such as Critical Thinking about the Paranormal, in which students are subjected to a series of cold readings and tested on their belief of the "psychic", who is eventually announced to be a fake.^[59]

Critical thinking is considered important in the academic fields for enabling one to analyze, evaluate, explain, and restructure thinking, thereby ensuring the act of thinking without false belief. However, even with knowledge of the methods of logical inquiry and reasoning, mistakes occur, and due to a thinker's inability to apply the methodology consistently, and because of overruling character traits such as egocentrism. Critical thinking includes identification of prejudice, bias, propaganda, self-deception, distortion, misinformation, etc.^[60] Given research in cognitive psychology, some educators believe that schools should focus on teaching their students critical-thinking skills and cultivation of intellectual traits.^[61]

Critical-thinking skills can be used to help nurses during the assessment process. Through the use of critical thinking, nurses can question, evaluate, and reconstruct the nursing care process by challenging the established theory and practice. Critical-thinking skills can help nurses problem solve, reflect, and make a conclusive decision about the current situation they face. Critical thinking creates "new possibilities for the development of the nursing knowledge".^[62] Due to the sociocultural, environmental, and political issues that are affecting healthcare delivery, it would be helpful to embody new techniques in nursing. Nurses can also engage their critical-thinking skills through the Socratic method of dialogue and reflection. This practice standard is even part of some regulatory organizations such as the College of Nurses of Ontario's Professional Standards for Continuing Competencies (2006).^[63] It requires nurses to engage in Reflective Practice and keep records of this continued professional development for possible review by the college.

Critical thinking is also considered important for human rights education for toleration. The Declaration of Principles on Tolerance adopted by UNESCO in 1995 affirms that "education for tolerance could aim at countering factors that lead to fear and exclusion of others, and could help young people to develop capacities for independent judgement, critical thinking and ethical reasoning".^[64]

The advent and rising popularity of online courses have prompted some to ask if computer-mediated communication (CMC) promotes, hinders, or has no effect on the amount and quality of critical thinking in a course (relative to face-to-face communication). There is some evidence to suggest a fourth, more nuanced possibility: that CMC may promote some aspects of critical thinking but hinder others. For example, Guiller et al. (2008)^[65] found that, relative to face-to-face discourse, online discourse featured more justifications, while face-to-face discourse featured more instances of students expanding on what others had said. The increase in justifications may be due to the asynchronous nature of online discussions, while the increase in expanding comments may be due to the spontaneity of 'real-time' discussion. Newman et al. (1995)^[66] showed similar differential effects. They found that while CMC boasted more important statements and linking of ideas, it lacked novelty. The authors suggest that this may be due to difficulties participating in a brainstorming-style activity in an asynchronous environment. Rather, the asynchrony may promote users to put forth "considered, thought out contributions".

Researchers assessing critical thinking in online discussion forums often employ a technique called Content Analysis,^[66][65] where the text of online discourse (or the transcription of face-to-face discourse) is systematically coded for different kinds of statements relating to critical thinking. For example, a statement might be coded as "Discuss ambiguities to clear them up" or "Welcoming outside knowledge" as positive indicators of critical thinking. Conversely, statements reflecting poor critical thinking may be labeled as "Sticking to prejudice or assumptions" or "Squashing attempts to bring in outside knowledge". The frequency of these codes in CMC and face-to-face discourse can be compared to draw conclusions about the quality of critical thinking.

Searching for evidence of critical thinking in discourse has roots in a definition of critical thinking put forth by Kuhn (1991),^[67] which emphasizes the social nature of discussion and knowledge construction. There is limited research on the role of social experience in critical thinking development, but there is some evidence to suggest it is an important factor. For example, research has shown that three- to four-year-old children can discern, to some extent, the differential credibility^[68] and expertise^[69] of individuals. Further evidence for the impact of social experience on the development of critical-thinking skills comes from work that found that 6- to 7-year-olds from China have similar levels of skepticism to 10- and 11-year-olds in the United States.^[70] If the development of critical-thinking skills was solely due to maturation, it is unlikely we would see such dramatic differences across cultures.

• Cederblom, J B.; Paulsen, David (2012). Critical Reasoning: Understanding and Criticizing Arguments and Theories (7th ed.). Andover, Hampshire, UK: Cengage Learning. ISBN 978-0495808787.
• Damer, T. Edward. (2005) Attacking Faulty Reasoning, 6th Edition, Wadsworth. ISBN 0-534-60516-8
• Dauer, Francis Watanabe. Critical Thinking: An Introduction to Reasoning, 1989, ISBN 978-0-19-504884-1
• Fisher, Alec and Scriven, Michael. (1997) Critical Thinking: Its Definition and Assessment, Center for Research in Critical Thinking (UK) / Edgepress (US). ISBN 0-9531796-0-5
• Hamby, B.W. (2007) The Philosophy of Anything: Critical Thinking in Context, Kendall Hunt Publishing Company, Dubuque Iowa. ISBN 978-0-7575-4724-9
• Vincent F. Hendricks. (2005) Thought 2 Talk: A Crash Course in Reflection and Expression, New York: Automatic Press / VIP. ISBN 87-991013-7-8
• Levitin, Daniel (2017). A Field Guide to Lies and Statistics. Viking. ISBN 978-0241239995. (a.k.a. Weaponized Lies: How to Think Critically in the Post-Truth Era)
• Moore, Brooke Noel and Parker, Richard. (2012) Critical Thinking. 10th ed. Published by McGraw-Hill. ISBN 0-07-803828-6.
• Paul, Richard. (1995) Critical Thinking: How to Prepare Students for a Rapidly Changing World. 4th ed. Foundation for Critical Thinking. ISBN 0-944583-09-1.
• Paul, Richard and Elder, Linda. (2006) Critical Thinking Tools for Taking Charge of Your Learning and Your Life, New Jersey: Prentice Hall Publishing. ISBN 0-13-114962-8.
• Sagan, Carl. (1995) The Demon-Haunted World: Science As a Candle in the Dark. Ballantine Books. ISBN 0-345-40946-9
• Theodore Schick & Lewis Vaughn "How to Think About Weird Things: Critical Thinking for a New Age" (2010) ISBN 0-7674-2048-9
• van den Brink-Budgen, R (2010) Critical Thinking for Students, How To Books. ISBN 978-1-84528-386-5
• Whyte, J. (2003) Bad Thoughts – A Guide to Clear Thinking, Corvo. ISBN 0-9543255-3-2.
• David Carl Wilson (2020) A Guide to Good Reasoning: Cultivating Intellectual Virtues (2nd edition) University of Minnesota Libraries Ebook ISBN 978-1-946135-66-7 Creative Commons Attribution-Non-Commercial 4.0 International License, at https://open.lib.umn.edu/goodreasoning/
• Zeigarnik, B.V. (1927). "On finished and unfinished tasks". In English translation Edited by Willis D. Ellis; with an introduction by Kurt Koffka. (1997). A source book of Gestalt psychology, xiv, 403 p. : ill.; 22 cmHighland, N.Y: Gestalt Journal Press. "This Gestalt Journal Press edition is a verbatim reprint of the book as originally published in 1938" – T.p. verso. ISBN 9780939266302. OCLC 38755142

• Butler, Heather; Christopher Pentoney; Mabelle P. Bong (September 2017). "Predicting real-world outcomes: Critical thinking ability is a better predictor of life decisions than intelligence". Thinking Skills and Creativity. 25: 38–46. doi:10.1016/j.tsc.2017.06.005. - See at ResearchGate
• Facione, P. 2007. Critical Thinking: What It Is and Why It Counts – 2007 Update
• Kompf, M., & Bond, R. (2001). Critical reflection in adult education. In T. Barer-Stein & M. Kompf(Eds.), The craft of teaching adults (pp. 21–38). Toronto, ON: Irwin.
• McPeck, J. (1992). Thoughts on subject specificity. In S. Norris (Ed.), The generalizability of critical thinking (pp. 198–205). New York: Teachers College Press.
• Mulnix, J. W. (2010). "Thinking critically about critical thinking". Educational Philosophy and Theory. 44 (5): 464–479. doi:10.1111/j.1469-5812.2010.00673.x. S2CID 145168346.
• Paul, R (1982). "Teaching critical thinking in the strong sense: A focus on self-deception, world views and a dialectical mode of analysis". Informal Logic Newsletter. 4 (2): 2–7.
• Twardy, Charles R. (2003) Argument Maps Improve Critical Thinking. Teaching Philosophy 27:2 June 2004.
• Patty Souza (2023) Critical Thinking. Teaching 11:5 June 2023.

• "Critical Thinking". Internet Encyclopedia of Philosophy.
• Zalta, Edward N. (ed.). "Critical Thinking". Stanford Encyclopedia of Philosophy.
• Zalta, Edward N. (ed.). "Informal logic". Stanford Encyclopedia of Philosophy.
• Critical thinking at PhilPapers
• Critical thinking at the Indiana Philosophy Ontology Project
• Critical Thinking: What Is It Good for? (In Fact, What Is It?) by Howard Gabennesch, Skeptical Inquirer magazine.
• Glossary of Critical Thinking Terms
• Critical Thinking Web