Legendary physicist Richard Feynman famously warned that when it comes to thinking, not fooling yourself should be at the top of your mind. His reason was simple: “You are the easiest person to fool”. Critical thinking is often hailed as the antidote to our tendency to self-deception. But it’s hard to pinpoint what people mean when they use the term. I’ve previously described it as the art of thinking and thinking about thinking to make judgements while improving the quality of the thought process itself. To illustrate the elusive concept further I’ve put together 26 quotes on critical thinking and added some personal reflections.
1. What Is Thinking?
Thinking — or reasoning — involves objectively connecting present beliefs with evidence in order to believe something else.
David T. Moore, Critical Thinking and Intelligence Analysis
If your thinking doesn’t get you into a different state of mind, even if it only means your existing convictions become more high-resolution, you were probably just ruminating; that is turning over the same thoughts without making progress.
2. Writing Is Thinking
If people cannot write well, they cannot think well, and if they cannot think well, others will do their thinking for them.
George Orwell
Skilful writing is indistinguishable from critical thinking as it forces you to clarify and reorganise your thoughts. But it also means that lazy writing leads to sloppy thinking, a bad habit George Orwell tried to address with his six writing rules.
3. Death of Ideas
The purpose of thinking is to let the ideas die instead of us dying.
Alfred North Whitehead
Thinking is akin to running simulations in our heads to test assumptions and predict outcomes. This allows us to pick the best courses of action. It’s superior to trying out hypotheses in the real world due to something called self-preservation.
4. Belief Confidence
The confidence people have in their beliefs is not a measure of the quality of evidence but of the coherence of the story that the mind has managed to construct.
Daniel Kahneman
We don’t naturally process ideas in terms of reasons, logic and arguments. We think in stories. So if you want to question the validity of your beliefs, start by questioning the story you’ve constructed around them.
5. Sagan’s Dragon
What’s the difference between an invisible, incorporeal, floating dragon who spits heatless fire and no dragon at all? If there’s no way to disprove my contention, no conceivable experiment that would count against it, what does it mean to say that my dragon exists? Your inability to invalidate my hypothesis is not at all the same thing as proving it true.
Carl Sagan, The Demon-Haunted World
Falsifiability is a cornerstone of critical thinking. If you encounter a statement or an idea that cannot be scrutinised let alone proven false, scepticism is in order. Thankfully, Sagan left us his Baloney Detection Kit, a set of cognitive tools for detecting falsehoods.
6. Dangerous Knowledge
Assumptions have been described as the most dangerous form of knowledge. Why? Because an assumption carries with it unconsidered information, knowledge that is not subject to thought or critique. However, assumptions are a fact of life; we all have them and we all rely on them. […] The best that we can do is identify them and make them explicit.
Charles Vandepeer, Applied Thinking for Intelligence Analysis
Another way to improve your critical thinking skills is to identify and question the underlying assumptions of a cherished belief you hold. For example by using Structured Analytic Techniques.
7. Passionate Opinions
The opinions that are held with passion are always those for which no good ground exists; indeed the passion is the measure of the holder’s lack of rational conviction. Opinions in politics and religion are almost always held passionately.
Bertrand Russell
The default state of our mind is to think about things intuitively and emotionally. While this helps us quickly solve complex problems using heuristics, it requires a deliberate effort to consider an issue rationally and logically. But the effort is worth it.
8. Building Blocks
When it comes to the ideas and opinions you hold, see them as toys or building blocks that you are playing with. Some you will keep, others you will knock down, but your spirit remains flexible and playful.
Robert Greene, The Daily Laws
For bad ideas to die, we have to see them less as precious possessions and more as means to the end of getting us closer to the truth.
9. The Utility of Scepticism
Science is more than a body of knowledge. It’s a way of thinking. A way of skepticely interrogating the universe with a fine understanding of human fallability. If we are not able to ask skeptical questions, to interrogate those who tell us that something is true, to be skeptical of those in authority, then we’re up for grabs for the next charlatan — political or religious — who comes ambling along.
Carl Sagan
A healthy scepticism is a civil necessity. But it’s worth remembering that the number one charlatan to look out for is still yourself.
10. Beware of Your Biases
People can be extremely intelligent, have taken a critical thinking course and know logic inside and out. Yet they may just become clever debaters, not critical thinkers, because they are unwilling to look at their own biases.
Carol Wade
Critical thinking without questioning and refining your assumptions, beliefs and ways of making judgements is not critical thinking. An integral part is becoming aware of your biases such as motivated reasoning.
11. Gut Feelings
Thinking for yourself is not limited to knowing your own biases and controlling how you come to analytical judgements. It also means to know when to use heuristics and trust your gut.
Gerd Gigerenzer
Gut Feelings are anything but arbitrary second-class ways of coming to a decision. Whenever it’s impossible to analyse or calculate risks and probabilities, the experience stored in your gut tends to be a good advisor.
12. Pseudo-Critical Thinking
Critical thinking, as has been noted, focuses on both the process and the results of reasoning. However, the term is also used in reference to reasoning that is not reflective. The application of formal logic is sometimes (incorrectly) equated to critical thinking. So too are problem solving and structured methods of analysis.
Developers of school curricula and other exponents of “sound thinking” often lay claim to the mantel of critical thinking but are really leveraging their coverage of logic or problem solving to capitalize on an uncritical understanding of what critical thinking is.
Problem solving, for example, focuses on answers and not on the process by which an answer is obtained. Additionally, logic or problem solving, being goal oriented, offer little means by which a person can improve the process of her thinking.
David T. Moore, Critical Thinking and Intelligence Analysis
Genuine critical thinking offers dual benefits. First, it allows you to make sound judgements and second, you improve your thinking in such a way that it’ll be easier for you to make sound judgements next time around.
13. The Intelligence Trap
Unintelligent people are more easily misled by other people, intelligent people are more easily misled by themselves.
Gurwinder Bhogal
The sharp-minded can rationalise their way to any bogus conclusions, crediting it to their critical thinking. The simple-minded adopt their views unquestioned while slamming others for their supposed lack of critical thinking.
14. Fruitless Philosophising
It is lacking in critical thinking to think that studying philosophy will improve your critical thinking.
Nassim Nicholas Taleb, The Bed of Procrustes
Merely curating a list of critical thinking quotes is unlikely to improve someone’s critical thinking skills. Like any skill, they have to be practised with a certain amount of skin in the game; that is a personal stake or risk exposure in the outcomes of their decisions or actions.
15. Overthinking
Most of us think compulsively all the time. That is to say we talk to ourselves. And I remember when I was a boy we had a common saying: ‘Talking to yourself is the first sign of madness.’
Now obviously, if I talk all the time I don’t hear what anyone else has to say. And so in exactly the same way, if I think all the time, that is to say I talk to myself all the time, I don’t have anything to think about except thoughts.
And therefore I’m living entirely in the world of symbols and I’m never in relationship with reality.
Alan Watts
Overthinking poses a cognitive hazard that can make you lose touch with reality. British philosopher Alan Watts knew that at some point, you have to put your stake into the ground and act.
16. Tragic Wisdom
The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.
Bertrand Russell
For all its benefits, an obsession with critical thinking can paralyse and make you second-guess every decision or action.
17. Intellectual Humility
Intellectual humility is the recognition that our reasoning is so flawed, so prone to bias, that we can rarely be certain that we are right.
Greg Lukianoff & Jonathan Haidt, The Coddling of the American Mind
We may not be able to overcome our biases but we should at least be aware of them.
18. Thinking for Yourself
You think for yourself first by learning a lot of the thoughts of other people. Other thoughts and ideas don’t pollute originality and independence, they create the preconditions for it.
The person who claims to think for himself, yet scorns learning from other sources, invariably is under the hidden influence of a source he doesn’t recognize. The only way to truly think independently is to have enough knowledge to spot the hidden assumptions that underwrite your current views.
Scott H. Young
In order to think critically you need something to think about. And this something tends to be thoughts, ideas or beliefs brought forward by other people, some of which you may even disagree with.
19. Intellectual Instruments
Everything we know has its origins in questions. Questions, we might say, are the principal intellectual instruments available to human beings.
Neil Postman
Good questions are the driving force of critical thinking, whether you ask them of others or pose them to yourself. The great thing about them is that they’re available to anyone.
20. The Critical Thinking Trap
People want you to think critically until you actually do it.
Chris Meyer
On the one hand, critical thinking is encouraged as a valuable skill because it leads to better understanding and decision-making. But when people apply critical thinking to commonly held beliefs or societal norms, it can challenge established perspectives. Truth is a virtue and the search for it demands non-conformist thinking. The fact that it can be at odds with the pressure of conformity is a feature, not a bug.
21. Freethinking
Freethinkers are those who are willing to use their minds without prejudice and without fearing to understand things that clash with their own customs, privileges, or beliefs. This state of mind is not common, but it is essential for critical thinking.
Leo Tolstoy
Freethinkers are often considered troublemakers challenging and disrupting the status quo. But it requires an open-mindedness that first and foremost causes trouble to their own values and opinions.
22. Downsides of an Open Mind
The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it.
Terry Pratchett
Having an open mind is generally considered a virtuous trait. But it also means you’re vulnerable to the influence of others who may attempt to indoctrinate your mind with their own agendas.
23. Indoctrination
Do not indoctrinate your children. Teach them how to think for themselves, how to evaluate evidence, and how to disagree with you.
Richard Dawkins
Despite being the antidote to indoctrination, critical thinking is useless without the knowledge and skills on how to disagree.
24. Cognitive Risk Taking
Take the risk of thinking for yourself, much more happiness, truth, beauty and wisdom will come to you that way.
Christopher Hitchens
Engaging in fearless critical thinking may be uncomfortable in the short term but is the better long-term strategy. However, that’s easier said than done if you haven’t set up your life to make a living as a gifted, chain-smoking and hard-drinking disagreeable contrarian. (We miss you Hitch).
25. Gramophone Mind
To exchange one orthodoxy for another is not necessarily an advance. The enemy is the gramophone mind, whether or not one agrees with the record that is being played at the moment.
George Orwell
A willingness to listen to other perspectives and change our opinions are the hallmarks of open-mindedness. But it’s not to be confused with passively accepting and repeating a different set of ideas without independent thought.
26. Changing Your Mind
Progress is impossible without change, and those who cannot change their minds cannot change anything.
Bernard Shaw
Those who are resistant to changing their views or beliefs will find it challenging to adapt to new circumstances.
BONUS: The Power of Your Mind
You have power over your mind — not outside events. Realize this, and you will find strength.
Marcus Aurelius, Meditations
There are few things over which you have control in this world. Your mind is one of them. So developing your critical thinking skills to influence your thoughts and actions is one of the best things you can do.
Closing Thoughts
Critical thinking is an elusive concept that is often diluted to mean “having opinions with which I agree”. In truth, it is self-reflective and deliberate thinking and thinking about thinking with the primary goal of not fooling yourself. For a deeper dive into the art of navigating the world of ideas to figure out what to believe, check out my post with 5 Books on Critical Thinking to Help You Develop a Reflective Mind and subscribe to the 3 Ideas in 2 Minutes newsletter.