Skip to main content

Critical Thinking

Why Should I Care?

When people hear something new, or read information, they need to evaluate that information, and their ability to evaluate the information. It's not easy. Especially when we are bombarded with new information every day. Being a critical thinker does not mean you are criticizing everything you hear. It means you are sorting what you know, from what you don't know, and what you trust, from what you don't trust.

This lesson has 5 parts

  • What is knowledge?
  • Knowledge level
  • Logic test
  • Bias Check
  • Critical Thinking Map

What is Critical Thinking?

This is a complex idea which might have different meanings to different people. For this reason, we will use three definitions of critical thinking, based in approaches used in the social sciences. Together, these three definitions will allow us to evaluate any statement or observation, in a disinterested, logical and unbiased manner.

First, critical thinking involves the use of available knowledge to sort between valid and invalid information.

Second, critical thinking involves the ability to determine if a statement is supported by the rules of logical reasoning.

Third, critical thinking involves the identification of bias in the process or the intentions, or interests of those who produce the statement.

  • What is knowledge?

According to the dictionary, knowledge is (1) the fact or condition of being aware of something, or (2) the range of one's information or understanding (Merriam Webster).

As scientists, it is important to differentiate knowledge from belief.

According to the dictionary, belief is (1) a state or habit of mind in which trust or confidence is placed in some person or thing, (2) something that is accepted, considered to be true, or held as an opinion, or (3) conviction of the truth of some statement or the reality of some being or phenomenon especially when based on examination of evidence (Merriam Webster).

In regular life, many people will use knowledge and belief as synonyms. Religious leaders often do, saying that they 'know' that God exists.

For scientists, knowledge represents the facts of life on earth that have been verified with the scientific method, and for which there are no other explanations. Knowledge is not set in stone, it evolves with every scientific discovery.

For scientists, beliefs are rather facts of life that may not be verified, and are usually not verifiable scientifically. Beliefs are therefore a function of trust. Scientists do not associate trust to knowledge, because it is not necessary to trust a fact that has been verified.

For example, someone points to a chair, and asks a scientist what this is. The scientist replies it's a chair. It looks like a chair, has the characteristics of a chair, and we can verify that it is not anything else but a chair. The scientist is using knowledge about chairs and can verify this fact. You don't need to trust someone saying this is a chair or not. You know it is.

In another example, someone brings their car to the mechanic, and asks about a bizarre noise coming from the rear of the car. The mechanic inspects the vehicle and says the coils to the suspension are broken and need to be replaced. The car owner cannot see the coils, and must TRUST the mechanic. The car owner thus believes the mechanic because he does not know if this is true or not, and he cannot fix it himself.

Having to believe someone puts us in a vulnerable position. This is why people are so upset when they feel betrayed by someone they trusted. When you have to trust someone else, your knowledge is low or lacking. Then you are bound to believe the person's statements, which makes you vulnerable to them. There are ways to evaluate their honesty, such as diplomas and protected professional titles, or reviews from neighbours and other clients.

Knowledge and Belief

 Verifiable
 Not verifiable
Trust
 n. a.
 Vulnerability / Belief
Do not trust
 Knowledge
 Suspect / Disbelief

  • Knowledge level

When you are confronted by a statement, you can use the first definition of critical thinking to self-evaluate your level of knowledge about the information.

Remember, critical thinking involves the use of available knowledge to sort between valid and invalid information.

So the first step is to ask yourself if you have alot of knowledge about this question. Try to rank yourself, as a subject expert, someone who knows alot, someone who knows a little, or someone who has absolutely no knowledge about this question.

If you know alot, then you can validate the information yourself. You can sort the information as valid, or not valid, on your own.

Remind yourself that no one knows everything about everything. No one can personally validate every single observation, or statement, that is proposed to them.

For example, you probably learned in school that the earth is round. Scientists have validated this and it's now part of human knowledge. However, you might not be able to validate this yourself. Have you ever been in outer space to look back on the earth to see if it's really round? Have you measured your shade, in different spots of the planet, to see if it's longer or shorter (this is a way to measure the earth's shape)?

Probably not. This does not mean that earth is not round. It just means that YOU actually don't know, for yourself.

  • Logic Test

Another way to validate a statement is to analyze its use of logical reasoning, which is a field of philosophy with very strict rules for using premises, arguments, statements, deductions, and conclusions. This is especially useful for arguments, but may not be useful for other types of statements such as observations (ex: is this a chair?).

A simple way to do this is to try and apply a logical fallacy to the statement proposed. Logical fallacies are faulty arguments based on poor logic.

For example, you can't observe if the earth is round or not, but you have taken flights and noticed that some of the flight paths were surprising. A direct flight from Toronto, Canada, to Mumbai, India, will fly over Nunavut, rather than fly over Africa. This is the kind of information that would not be logical if the earth were flat. This is called a demonstration a contrario, using a contrary argument.

  • Bias Check

Third, critical thinking involves the identification of bias in the process of making the statement, bias in the intentions of the person making the statement, or interests of those who produce the statement.

Money is a major factor that influences people. Follow the money, and you will probably find reasons to doubt of the validity of a statement. University professors are not volunteers. They are well paid by their universities. However, this allows them to be independent from outside money. They are not supposed to accept money from political or industrial lobbies to further their agendas.

Other forms of bias can include personal preferences, cultural history, group affiliations, or political interests.

Look for a disclaimer of any potential conflicts of interests. Look for sources of financing. Cross-reference the author's political leanings or affiliations.

  • Critical Thinking Map

Here is a three step decision tree that can help you be a thorough critical thinker.

 

 

 

 

 

 

References and Further Reading

Merriam-Webster Dictionary Online (2023). Belief. https://www.merriam-webster.com/dictionary/belief

 

Back to top