In this article I interview British Philosopher Martin Cohen, PhD, author of Critical Thinking skills for Dummies, Philosophy for Dummies, 101 Philosophy Problems, Philosophical Tales and Wittgenstein’s Beetle. Martin is editor of The Philosopher and current Visiting Research Fellow in Philosophy at the University of Hertfordshire.

In this article:

Let’s begin:

What is Critical thinking?

Michael Frank: I’d like us to start with a definition of terms. What is critical thinking?

Martin Cohen: That’s actually something that people don’t really agree on.

For me critical thinking is about several different abilities:

The ability to recognize what is relevant

Being open minded and able to appraise evidence

Being able to fairly evaluate arguments

Flexibility of thinking

If I were to sum it up in a sentence: Critical thinking is about thinking outside the box.

Michael Frank: I see critical thinking as:

Analyzing information for truth and accuracy

Questioning: Assertions Assumptions Data/facts/figures How information is positioned/presented/framed/spun The narrative



I see critical thinking as like a firewall for your mind. It doesn’t stop the truth from getting in, it just stops lies and BS from getting in.

Martin Cohen: Well what you just described is John Stuart Mill’s definition of critical thinking. He said that everyone has to play devil’s advocate and ask questions about any information they receive and look behind the information they receive. So it’s this idea of critical thinking as a kind of intellectual self-defense.

Michael Frank: I think intellectual self-defense is a pretty cool definition!

It’s not just spotting logical fallacies

Michael Frank: You said in Critical thinking for Dummies that critical thinking isn’t just spotting logical fallacies

Martin Cohen: Yes because the trouble with logical fallacies is that the world is far more complicated than that, and what is actually valid is often empty. So sentences are taught that are logically valid, but that are absolutely useless in real life, and sentences that are perfectly useful, are often full of fallacies.

As Daniel Kahneman pointed out in Thinking Fast and Slow, most people think fast instead of logically, and what philosophers often propose doesn’t apply to actual real issues in the world and there’s a gap between real language and logical language which many logicians never seem to come to terms with.

Michael Frank: So there are things that look right on paper & sound good in theory, but are not necessarily practical or useful in real life

Martin Cohen: Exactly

Why is it important to be a Critical thinker?

Michael Frank: Why is it important to be a critical thinker?

Martin Cohen: Two reasons:

So you can avoid being fed false information. We are surrounded by poor information and it’s actually a very big achievement to defend yourself from it So you can find your own insights

The 4 principles of Critical thinking

Michael Frank: If you were to build the perfect critical thinker in a lab, what habits or what qualities would they have?

Martin Cohen: I recommend four principles:

They’re tolerant and open-minded to new ideas. There are many people who describe themselves as critical thinkers who dogmatic and intolerant and quick to jump on anyone for the slightest fallacy. But that to me is not a true critical thinker. A critical thinker wants to give people the space and freedom to let them develop their ideas, and to allow them to express more information which can then be evaluated They don’t waste time trying to win arguments. They don’t want to win the argument. They want the truth. And they’re two different things Rationality. They avoid emotional arguments, personal attacks, and stick to the facts Take your ego out of it. Often when we’re talking to someone about an issue, we end up becoming more interested in being right, than we are in getting to the actual truth of the matter. However we should try to identify and acknowledge the good parts of our opponents argument, and then work together to build an even superior position to either argument that you started with. That’s a cooperative, collective, team approach, which is unfortunately not seen much in academia where everyone is always competing

Michael Frank: So not trying to compete with one another, but trying to work together to come up with a superior idea.

Martin Cohen: Yeah.

Michael Frank: I like that idea. Take your ego out of it. I try to do that myself. I look at arguments and beliefs as a series of premises, and I’ll happy steal the best ones from my opponents in order to get to get as close as I can to Truth with a capital “T”

I’d also probably add a couple points:

You need to have an understanding of logical fallacies and cognitive biases

You should have no sacred cows. There should be nothing off-limits or above questioning

4 rules for argumentation

Martin Cohen: I’d also like to share my four rules for argumentation:

Don’t use anything except arguments to advance your position. Don’t try to appeal to people’s prejudices or fears. Too often people try to win arguments with emotions or by using fear. Don’t straw man the other person. Don’t attack positions that no one has put forward. No matter how easy or fun it is or how clever it makes you look. Don’t knock down a position that the other person isn’t holding. Defend and justify your position with proper reasoning. You must have an openness to defend your position with proper reasoning. Don’t refuse to backup or justify what you are saying. Don’t stop your opponent from advancing a new position or challenging your position. Certain views are now being shut down in society as unacceptable. I’m seeing academics who have respectable positions being hounded out of their jobs in the West, losing their positions, losing their titles, because of this PC censorship that is creeping on coupled with the political environment.

This business of encouraging dispute and debate, which is what goes back to Socrates (who remember met a sticky end) is what we must always respect. We must have vigorous debates in society, real debates with people putting views that other people don’t like.



Critical thinking questions

Michael Frank: What are some good critical thinking questions we can ask ourselves when we’re watching the news, listening to a podcast, reading a book etc.?

Martin Cohen: Well when you’re reading a book you can ask:

Why did the author write this book?

What is their reason or motivation for writing it?

What background perspective are they starting from?

What is my own reason for reading it? Why did I pick this book? What beliefs, assumptions, prejudices etc. got me to choose this book? Am I trying to confirm or reinforce some view of my own?

Is this the consensus opinion? Or is it a minority opinion?

Is it arguing in a rather skewed way?

Is it presenting opinions as facts?

Michael Frank: I love that. Not just what is the author’s motivation for writing the book, but what is your reason for reading it? We must avoid confirmation bias

Critical thinking tips

Michael Frank: What are some of your favorite critical thinking tips?

Martin Cohen: I would say examine all of the ways you might be engaging in self-deception, and examine your real reasons and motivations for doing things, not just the reasons you present to yourself and others.

American philosopher William James said that when people normally offer their reasons for doing something, what they’re normally doing is rearranging the prejudices.

Develop emotional intelligence

I would also add that people should try to develop emotional intelligence along with any attempt to think more logically or rationally.

If you’re talking to other people emotional intelligence often enables you to understand what they’re saying and why. You can see their position and then extract the value in what they’re saying and that is a very good way for both of you to progress to a better understanding of things.

Beware of problem formulations and framing

I also think it’s important to note that people often make very little progress on a problem simply because of the way it’s been formulated or presented to them.

When go back a step and restate the problem in a freer way, it opens up your perspective, and suddenly possibilities multiply.

Michael Frank: So question your starting assumptions and the way the problem or question has been formulated

Martin Cohen: Yeah. We are locked in a prison of our language, and our thoughts can only go so far because they follow on certain linguistic ruts or tram lines created by our language.

Einstein said that the mere formulation of the problem is far more essential than it’s solution which is a very good quote. At school we’re given the questions and then we’re told to find the solutions. But in real life it’s actually far more useful to find the right question.

Michael Frank: Exactly

“If I had one hour to save the world, I would spend 55 minutes defining the problem and only five minutes on the solution” – Albert Einstein

Three types of thinking to avoid

Michael Frank: In terms of critical thinking errors or mistakes, what are some things we should watch out for or avoid?

Martin Cohen: Charles Sanders Peirce talked about three kinds of thinkers you don’t want to be:

The stickler: We all know people like this. It doesn’t matter what the facts are, they want to insist on whatever idea or position they liked the most originally, and they’ll seek out books and videos and friends to support their position. This is essentially a closed-minded person who has probably taken up a position on something too quickly without knowing the facts when they started. The follower: It’s not that you’re clinging to your position, it’s even worse, you’re clinging to someone else’s. Whomever you imagine to be an expert or authority. So you don’t listen to counterarguments because you say (insert authority or expert) has said such and such. Take climate change for example, people will insist that the issue of climate change is beyond their judgment, that it has been judged factual by the experts, and how dare anyone try to think about it independently. And so a lot of people are not thinking about climate issues independently, instead they’re delegating the matter to other people. But I think that is always a dangerous thing. System builders: People who will entertain new ideas but only if it fits into the pre-existing structures. So you get some new information and then you try to fit it within the box that’s already been presented to you. The problem is that the problem has already been formulated so you’re not able to come up with your own problem definition. You’re just starting with the assumptions presented to you. So if you’re a system builder you can’t think outside of the box when you need to. You have to distort the information in order for it to fit, but it hasn’t really fitted in and you’ve misled yourself and you may actually have some disaster down the line.

Michael Frank: I’ll recap the three thinking habits to avoid:

Sticklers: People who like whatever idea they’ve adopted originally, and will stick to it at all costs and will resist any other idea no matter what

Followers: People who believe whatever the “authorities” and “experts” tell them to believe

System builders: People who will think for themselves, but only within the preexisting frames/box that’s been presented to them. They don’t question the box that’s been presented to them, they just try to think within the box. Even if they have some intelligent solutions, it always comes within the box

Martin Cohen: Yeah they’re open to new information, but they always try to look at it from a perspective that says it must fit in with other information

Michael Frank: I also think a good general rule of thumb is that your thinking should not be bound by the parameters of the question

What does it mean to “know” something?

Michael Frank: Socrates said: “The only thing I know is that I know nothing”. But I honestly don’t even know what the hell it means to know something. What does it mean to “know” something?

Because this is what I’ve come to realize: People falsely equate certainty with knowledge. In other words: When people say “I know it”, what they mean is “I’m 100% certain of what I’m telling you and there’s nothing that can change my mind”

But being 100% certain about something doesn’t mean you know something. People are 100% certain about things all the time and they’re wrong.

Martin Cohen: What people tend to say is “I know it” and here is my reason. Sometimes we have good reasons, and sometimes our reasons are actually mistakes or errors.

Scientists can have lots of evidence for their theories, and then they find a flaw in their theory, and even though there was lots of evidence for the theory, it wasn’t really right and has to be reassessed. You can have so many layers of reassessment that you will tend to find that you can never get to rock bottom certainty.

Michael Frank: Yes there is always the possibility of new evidence presenting itself in the future, which clarifies or revises or contradicts our current view of reality. We say that we know all these things all the time and I’m not sure that we do. We can feel certain about things. We can agree upon an objective view of reality. But I still don’t know what it means to “know” something.

Martin Cohen: I don’t think there is an answer to it. What scientists do is they tend to work in probabilities. But what is a probability? It’s a sort of slightly meaningless concept in many ways. You end up with the idea that real certainty doesn’t exist unless you go to theology and that’s a very dangerous step to take.

Science doesn’t “prove” anything

Michael Frank: One of the most common misconceptions about science is that science “proves” things. Whereas in reality science doesn’t “prove” anything. Science deals in probabilities, not proofs.

I want to know:

Is there such a thing as “proof of truth” with a capital “T”? (Objective truth)

You can have evidence for something. Sure. But evidence isn’t proof. Proof to me means something that can’t be contradicted. It’s undeniable. It’s unquestionable. It’s irrefutable.

Martin Cohen: Here’s a logical proof. We’ve got an argument with three premises:

Premise one: Red berries are dangerous for humans to eat

Premise two: Raspberries are a kind of red berry

Premise three: Therefore, raspberries are dangerous

I’ll ask you a question: Is the argument valid or invalid?

Michael Frank: The argument is valid, but obviously we know from real life that raspberries aren’t dangerous, however the argument is valid, yes.

Martin Cohen: This is the thing, this search for certainty, which is why I go into this tangent, can’t really be settled by using logic, because yes it’s a perfectly good logical argument, but the problem is that first premise “red berries are dangerous to eat”, there’s a vagueness in there. Is it some red berries? Is it all red berries? It’s not stated. And it’s that vagueness that makes logic not that powerful a tool for everyday living that we pretend it his.

Logic vs Truth

Michael Frank: So logic is not the be all and end all when it comes to discovering or knowing truth with a capital “T”? That would be fair to say?

Martin Cohen: I would say yes

Michael Frank: Ok double question:

Can something be logical and untrue? (as with your premise)

Can something be illogical and true?

Martin Cohen: Logic exists in a separate sphere. It’s mathematics. And the thing about mathematics is that it’s a closed system. You start with axioms, like Euclid’s axioms, and then everything has to be to be deduced from there. And then eventually you come to a situation which Einstein came to, which was that you couldn’t prove anything about relativity within Euclid’s maths.

Relativity is based upon an alternative maths, and the whole of modern physics is based on two mathematical systems which are incompatible. They’re logically coherent within themselves, but the two systems are not compatible with each other, so they’re incoherent in a broader sense, but we live with lots of systems which are all incoherent all the time. And we apply logic only to one bit because if you try to apply it to the whole thing, then it’s impossible.

The scientific method

Michael Frank: A lot of people claim that the scientific method is the only reliable and valid way of attaining truth. However that claim itself cannot be demonstrated via the scientific method. And if something can’t be replicated and tested and experimented with, it’s of no use to the scientific method.

Do you believe that the scientific method is the only reliable and valid way of attending truth? And if not, what might be some other ways of attaining or knowing truth?

Martin Cohen: The scientific method is powerful, but in another way it’s very limited, and part of its power is that it recognizes it’s limitation, and it will cheerfully – when it’s working – throw away everything it’s built up and start again. The myth of science is that it accumulates in a smooth progression. Take standard textbooks, if you look at the ones that were printed 20 years ago, very little in it is correct. So that rate of which opinion changes in science is far greater than what we are really aware of because we’re not experts.

Philosophy looks at things slightly differently. We’ve got these questions that are 3000 years old, and we’re still talking about the things people wrote back then. What sort of a subject does that? Why is it possible that texts by Aristotle and Plato are still as good as anything modern? That’s a very unusual thing and in a way it’s also a very bad thing. It says that there hasn’t been any progress on these issues. These same questions still have not been settled.

Michael Frank: Maybe in regards to these seemingly eternal philosophical questions, we maybe posing the question incorrectly, and maybe a restating of the question might yield a different answer, or it could just be that the information required is outside, or currently outside, of our grasp.

I want to come back to the scientific method though.

What might be some other ways of attaining or knowing truth in addition to the scientific method?

Martin Cohen: Science in a way, is a kind of story in which the statistics are decorations, because the statistics can often be challenged later and the statistics only refer to one setup, one framework, one time, one group of people.

And the universe is infinite and you’ve got so many different factors. There’s always this attempt in science to strip down things and to reduce the number of factors, and as you do that, it ceases to relate to the world.

So the idea that science has got a superior grip on knowledge, is I think an understandable fiction that we cling to, but the reality is that the world is multidimensional, it’s many factors, very complex, and it’s quite possibly the case that science is actually misleading us in exactly the way that a critical thinker is supposed to be wary of. Rather than us thinking that science has some special access to truth, I think we need to understand that you need to keep a philosophical background in your approach and keep the scientists at arm’s length.

This interview has been edited and condensed for clarity.

Martin Cohen is an author, editor and educationalist who has written many books in philosophy and social science including the bestsellers, 101 Philosophy Problems, an “anti-history” of great philosophers, called Philosophical Tales and Wittgenstein’s Beetle, all widely translated. He has written two popular reference works for the Dummies series, Critical Thinking Skills and Philosophy (UK and rest of world edition).

A committed environmentalist, he has written discussion papers on environmental concerns for the European Parliament, a series of articles in the Times Higher (London) about the politics of the climate change debate and has been invited by the Chinese government to discuss ecological rights and indigenous communities.

Martin is also the editor of The Philosopher, a journal founded in 1923, which counts some of the best known names in Twentieth Century philosophy amongst its contributors, and co-editor of Philosophical Investigations. His editorial strategy, as with is books, is to allow as wide a range of ideas as possible a forum, and he often prints papers by non-specialists with unusual and original ideas.

He works partly in the UK and in France where he lives with his wife, one young philosopher and a cat. His latest book is ‘I Think Therefore I Eat’ (Turner 2018).