What is CT?

Definition
Simply put, critical thinking (CT) is figuring out how likely it is that a given fact claim is true.

To do this, you have to learn concepts, develop skills, adopt ethics, and recognize barriers, but more on that in a bit.

Like reading or writing, CT is independent of any particular subject. You can apply CT to fact claims in any domain. You can teach CT in any subject.

CT must be learned
We aren’t born good critical thinkers, nor do we naturally turn into them. Like riding a bike or singing a song, to do CT well, we have to learn and practice until it becomes habitual.

Here are some reasons why CT doesn’t just come naturally:


 * Some reasons why:
 * Childhood credulity:  We evolved to uncritically accept what adults tell us, and for good reason. When a parent tells a child that running into the street is dangerous, it’s good that the child believes it without testing it out themself. The flip side, though, is that children can also readily accept false information, leading to misinformed beliefs that may persist through adulthood.  You can read more about childhood credulity here.


 * Common thinking errors: A large body of psychological and neuroscientific research has established that most of us are prone to a host of errors in logic, perception, estimation, and memory.  All of these are barriers to critical thinking. You can read more about thinking errors here.


 * Non-intuitive concepts:  Critical thinking relies on knowledge that took hundreds or even thousands of years of cumulative thought to develop, like math, the scientific method, and formal logic.  Moreover, these concepts continue to evolve. This knowledge does not come to us naturally.

Becoming a good critical thinker
Becoming a good critical thinker involves learning concepts, developing skills, adopting ethics, and recognizing barriers. Students can start doing all of these things in kindergarten and continue throughout their educational career. Basic, intermediate, and advanced examples of each activity are given below.

Learning concepts
Basic: Facts and claims. First-hand and second-hand evidence.

Intermediate: The qualities of sound methods. Casual and scientific evidence.

Advanced: Prior plausibility of a fact claim. Probability of outcomes.

Developing skills
Basic: Using sound methods. Hypothesizing. Gathering evidence.

Intermediate: Devising sound methods. Evaluating evidence. Devising arguments.

Advanced: Calculating probabilities. Identifying thinking errors in arguments. Identifying the expert consensus.

Adopting ethics
Basic: Valuing knowing the truth over winning an argument. Honesty.

Intermediate: Evaluating arguments on their merit, regardless of the motive behind them. Intellectual humility.

Advanced: Intellectual charity. Civil discourse.

Recognizing barriers
Basic: Memory errors. Arguments from authority.

Intermediate: Motivated reasoning. Arguments from ignorance.

Advanced: Your own biases. Insufficient or skewed access to information.

The language of CT
Like many subjects such as geometry or physics, CT uses precise terms like “indirect evidence”, “fact claim”, and “confirmation bias” to describe things. By establishing a common language of CT, the knowledge, skills, and ethics it requires can be transferred from one subject to another and from one context to another. Click here to learn more about the language of CT.