What Is Critical Thinking?

1. The Historical Development of Critical Thinking

When you decided to study critical thinking, you might not have imagined that you would first have to define critical thinking. "It's just thinking clearly and carefully!" you might guess. Or it's thinking outside the box, or being open-minded, or making decisions based on logic instead of emotion.

think about it

Do you have a working definition of “critical thinking”? How would you describe it to someone?

In fact, all of these definitions are correct but incomplete. The idea of critical thinking has been in development for thousands of years, and it defies easy summary. In order to fully understand what we mean when we speak of critical thinking, we have to begin with the origins of the idea.

Critical thinking, as an explicit term, has its roots in John Dewey’s work from the early 20th century. Dewey introduced the term (also called “reflective thinking”) as an educational goal, which he understood to be a scientific attitude of mind. He defined critical thinking specifically as:

people to know

John Dewey

John Dewey (1859-1952) is sometimes called “the father of critical thinking.” His works of philosophy range across many disciplines, but he is best known for his work in educational reform. His vision for both how students learn and how teachers are trained radically changed the field of education.

While the term "critical thinking" was new, the concept was not. Dewey quoted older sources like Francis Bacon (1500s), John Locke (1600s), and John Stuart Mill (1800s), implicitly noting that there is a long history of the development of critical scientific methods of thinking.

In order to develop our own working definition of critical thinking, let’s overview a brief history of logic and critical thought. Western critical thought and logic (at least that we know about) probably started with the teachings of Socrates almost 2,500 years ago.

people to know

Socrates

Socrates was an ancient Greek philosopher who lived in the city state of Athens in the fifth century B.C.E. He is often called the father of western philosophy for his method of inquiry called dialogues, in which he engaged in conversation on topics of morals and ethics and, through questioning, revealed truths. Though he never authored a single text, his work is known because his protege, Plato, wrote down many of his dialogues.

Socrates established the importance of asking deep questions that probed into standard assumptions and patterns of thinking. He established the need for evidence-based thinking aided by closely examined reasoning.

Socrates' student Plato went on to be the teacher of Aristotle, who is credited with developing one of the earliest components of critical thinking: logic. Modern critical thinking is essentially tied to logic. Logic is reasoning by way of a set of rigid rules. Logic has a long history both in the Western and Eastern traditions. Historically, some of the earliest formal logics were developed in ancient Greece, India, and China. In Ancient Greece, Aristotle was the first Western formal logician. His logical theories are called logical because they rely on grouping and classification, such as “all dogs are mammals, and all mammals are animals. Therefore, dogs are animals.” He analyzed the logical structure of arguments and articulated the rules that govern good arguments. Modern categorical logic is derived from Aristotle’s original teachings.

people to know

Aristotle

Born in 384 BC, Aristotle is a student of Plato and a critically important ancient Greek philosopher. His writings covered a vast number of subjects, from biology to ethics to logic.

Meanwhile, in ancient India in the sixth century BC, independent of the scholastic developments in ancient Greece, the Nayaya school introduced a form of logical analysis called the five-membered schema. Like Aristotle’s categorical logic, this was a way of analyzing logical structure for the rules of good argumentation. Further, logic was initially developed in the ancient Chinese tradition in the fifth century BC by Mozi. Mozi founded the Mohist school, whose logic tradition focused on solving logical puzzles. The Mohists were also the first to use notation for logical arguments.

term to know

Logic

Reasoning by way of a set of rigid rules.

2. A Working Definition of Critical Thinking

Since Dewey’s introduction of the term "critical thinking," there has been much disagreement over what the exact definition should be. Let’s begin our analysis of the definition of critical thinking with a simplified form of Dewey’s definition. We can broadly think of critical thinking as:

Reasoning is the act of thinking in an active, persistent, and careful way.

Here, belief is confidence that a statement is true or that something exists; there are richer, more complex meanings of belief that will be described later.

We can think critically about any belief or piece of knowledge that we have. Suppose we think critically about our belief that all people should have the right to vote. This would involve us thinking about the evidence we have that supports the idea that all people should have the right to vote and what conclusions that belief would entail. For example, if all people had the right to vote, that would mean that felons should be allowed to vote, that voting days shouldn’t conflict with people’s work schedules, and polls shouldn’t close until everybody has had the chance to vote—none of which is currently true in the United States.

We will refine our definition further below, but first we will look at what critical thinking entails.

terms to know

Critical Thinking

Reasoning about any belief, the evidence that supports that belief, and the conclusions that it supports.

Reasoning

The act of thinking in an active, persistent, and careful way.

Belief

Confidence that a statement is true or that something exists.

3. Thinking Processes Involved in Critical Thinking

There are a variety of different tools and techniques we can use to think critically. Three broad categories of thought processes involved in critical thinking are listed below.

1. Questioning: The art of interrogating a subject, idea, or belief. Good questioning involves curiosity and creativity. There are two main kinds of questions that one can ask: open questions and specific questions. Open questions require the respondent to elaborate on a given point. These include questions such as: “What you think of…?”, “How does that relate to…?”, and “Why do you think… is true?” Specific questions, on the other hand, ask for a concrete answer. They are not open-ended and usually focus on clarification or description. They include questions such as: “Is… true?”, “What does… mean?”, and “How are you defining…?” Good questioning ultimately encourages creativity (thoughtful and original approaches to an issue), and introspection (careful interrogation of our own beliefs and thinking).

EXAMPLE

Consider the simple statement from the Declaration of Independence, “All men are created equal.” This statement can be questioned with open-ended questions like, “Why do you think this is true?” or "What do you hope to achieve by stating this?" It can also be questioned with specific questions like, “What do you mean by ‘equal’?” and even “What do you mean by men?” The answer to the second question has particularly evolved since Thomas Jefferson wrote this famous statement!

2. Analyzing: The process of examining a subject or belief, understanding it, and being able to explain both the belief and its implications. Analyzing belief is at the core of critical thinking, and there are a variety of ways we can go about this analysis. We can compare and contrast, break an idea down into its parts, and consider implications and evidence for that belief. We can also analyze the questions we have about a particular idea or subject by determining what may or may not be a good answer to each question and what answering the question involves. Analysis is the substance of critical thinking, and you will find as we proceed with the course that the formal and informal logical approaches we discuss are geared toward analysis.

EXAMPLE

In the previous example, we questioned the meaning of the statement, “All men are created equal.” In analyzing this statement, we might ask questions like, “What role does the government play, if any, in protecting this equality?”

3. Concluding: Forming an opinion, belief, attitude or determining a novel fact about a subject or idea. Drawing a conclusion can involve evaluating the quality of an idea in forming a value judgment, inferring new information from what is given in the subject or idea, synthesizing given information to determine a novel fact, and creating new ideas, arguments, and/or broadening one’s horizons in a particular subject matter. Crucially, what’s important to concluding is that it relies on sound analysis and open-mindedness. Open-mindedness requires monitoring our own thinking to make sure that we are open to every possibility, every kind of information, and every kind of alternative or approach, and are not wedded to our own preconceived opinions.

EXAMPLE

Throughout American history, different people have drawn different conclusions about the implications of “all [people]” being “created equal.” Some may think it means only that everybody is treated the same under the law. Others have concluded that to support this statement, we must ensure that all people all have equal opportunities, such as access to education. Either conclusion requires rigorous questioning and analysis to support the conclusion.

terms to know

Questioning

The art of interrogating a subject, idea, or belief.

Open Questions

Questions that require the respondent to elaborate on a given point. These include questions such as, “What you think of…?”, “How does that relate to…?”, and “Why do you think… is true?”

Specific Questions

Questions that require a concrete answer and may have a factual answer. These include questions like, “Where were you on the night of June 5th, 2017?” and “What is the capital of North Dakota?”

Analyzing

The process of examining a subject, idea, or belief in question, understanding it, and being able to explain both the information and its implications.

Concluding

Forming an opinion, belief, attitude or determining a novel fact about the subject or idea in question.

Open-Mindedness

Monitoring your own thinking to make sure that you are open to every possibility, every kind of information, and every kind of alternative or approach, and are not wedded to your preconceived opinions.

4. A Refined Definition of Critical Thinking

Now is the time to further define critical thinking as:

When critical thinking is defined as active, persistent, and careful, we mean that critical thinking is a process of one’s own mind that takes considerable time, focus of attention, and mental and personal energy. Critical thinking is not easy, quickly performed, or without cost. Good critical thinking is essential to the humanities and sciences, and it takes considerable training and experience to become skilled at it.

By saying that critical thinking includes finding out as much truth as possible, it must first be noted that everything that we think about requires information. When a problem must be solved, it is important to know what the problem is. This is done by gathering information about the nature of the problem itself. When a good decision needs to be made, it is important to gather all possible information about every available alternative, so we have a good chance of making the best decision.

EXAMPLE

A regular use of critical thinking is in managing money and setting a budget. We need information (such as about our expenses and our income) and must make sure the information is accurate. We constantly ask questions (Do we need this item? Can we get it cheaper?). Anytime something changes—a raise, a rent hike, or something else—we have to revise the budget.

Information may be true, false, or misleading. A misleading statement (or misinformation) is often false but may be factually true while leading to the wrong conclusion. For example, a politician may declare that their opponent voted against a bill to compensate veterans. In fact, the opponent voted against the bill in favor of a stronger one that would do more to compensate veterans. The statement is true, but intentionally misleading. To have our best chance of successfully analyzing our subject and coming to good conclusions, we need the information to be both truthful and accurate.

EXAMPLE

Imagine you are a general at war with your neighboring country. During a key battle, it is reported to you that the neighboring country’s forces appear to be making an all-out attack on your army’s flank. So, you decide to call all your troops to your flank to repel the attack. Unfortunately, the appearance of an all-out attack on your flank was, in truth, a diversion with most of your neighboring forces attacking your rear and winning the war. You lost the war, lost your country, lost the lives of many troops, and maybe lost your own life by relying on misleading information. If you knew the truth of the all-out attack on your flank as truly a diversion, you would have had your best chance for making the right decisions on how to fight the battle and win the war.

Although few of us will be making key military decisions, we are constantly bombarded with misleading information that can lead to poor decisions.

It is also important to make sure that you have sufficient truthful information to think critically about a subject. It is not unusual to find that the truthful information you have been able to gather is not enough to solve the problem, make the right decision, make a quality evaluation, or result in that new discovery. If our good critical thinking tells us that we need more truthful information to be successful in making the right decision, for example, we should seriously consider deferring that decision for a later time when we have the needed truthful information.

EXAMPLE

At the start of the COVID-19 pandemic in 2020, every business and institution was faced with tough decisions about what to do in response to the public health threat. There was a lot of confusion and disagreement, and the biggest reason for the confusion and disagreement was that we did not have much information about the virus at the time. Unfortunately, those decisions had to be made before we knew more, leading to rapidly changing information.

think about it

Imagine that you are hearing unusual noises in your car engine just before a long road trip. Is it serious enough to delay or cancel the trip? How can you make a decision without more information?

Now that we have a definition, why is critical thinking important in your life? And how do you practice good critical thinking? These questions will be answered throughout the course.

terms to know

Critical Thinking

Thinking in an active, persistent, and careful way about any belief, the evidence that supports that belief, and the conclusions that it leads to, which is in part directed at finding out as much relevant, truthful information as practically possible.

Misinformation

Information that may be outright false or misleading, being factually true but leading to a false conclusion.

REFERENCES

Hitchcock, David, "Critical thinking", The Stanford Encyclopedia of Philosophy (Fall 2020 Edition), Section 3. Edward N. Zalta (ed.), URL = plato.stanford.edu/archives/fall2020/entries/critical-thinking