The Art of Thinking Clearly by Rolf Dobelli [Actionable Summary]

This is a comprehensive summary of the book The Art of Thinking Clearly by Rolf Dobelli. Covering the key ideas and proposing practical ways for achieving what’s mentioned in the text. Written by book fanatic and online librarian Ivaylo Durmonski.

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The Book In Three Or More Sentences:

A book based on the realization that we systematically fail to think clearly. After meeting Nassim Taleb, a desire to understand heuristics and biases boomed in the author’s mind and lead to a transition. From a novelist, Rolf Dobelli became a student of social and cognitive psychology. This book is a compilation of 99 systematic cognitive errors (thinking errors) that aim to give you the upper hand in any given situation.

The Core Idea:

We need less irrationality. Nothing else to improve our daily lives. By understanding what you’re likely to do wrong, and by evading these corrupting behavior patterns, you’ll find yourself absurdly productive and move closer to where you want to be.


  • We prefer taking risks with something familiar rather than trying something new because of uncertainty.
  • Success is rarely due to what’s visible. There’s always something else happening in the background.
  • Experts don’t know everything. What they share is based on their field. Blindly following their advice can be harmful.

5 Key Lessons from The Art of Thinking Clearly:

Lesson #1: The Cause of Something is Never One Thing

Your conclusion after a distressful event usually ends up something like this: “John, the product manager, is responsible for the slow sales this season – nothing else. We should fire him!” Or, “I have a flat tire because my husband failed to check the tires this morning.”

We tend to blame one thing, or one person when something bad happens. But usually, there’s more going on.

  • Fallacy of the single cause: We imagine that our actions are enough for something to happen – to win an award or to outwit the competitors. We think that one simple thing can cause a major positive change. But that’s rarely the case. No singular event can help you triumph and win the day. Even if we don’t immediately see them, there are always a lot of factors involved in any given situation.
  • Ambiguity aversion: With everything else being equal, the scale will tilt towards what’s familiar. Even if there is risk involved, you’ll choose to take your chances rather than trying something new, something unfamiliar. The ambiguity aversion thinking error explains that we prefer taking risks with familiar things, even if the new, foreign strategy can lead to much better results.
  • Affect heuristic: We’re not in control of our actions. Our emotions are. You might think that you’re a reasonable person. That your decisions are based on carefully calculated data that’s analyzed in your brain but in most of the cases small things like, the weather outside, can hugely influence your judgment. So, instead of asking yourself, “What do I think about this?” use, “How do I feel about this?”

Lesson #2: Outside Information Influences our Decision-Making

News, friends, commercials, street signs, the words printed on our 5 dollars t-shirt from the local store, the sticky note on your cubicle.

Everything matters.

Everything we consume affects our judgment and can rearrange the thoughts inside our heads.

Sometimes you don’t need to get a complete 360-degree view of the situation. Actually, a lot of times, when something important needs to be decided, it’s best to remain on your own. With your own thoughts to make your mind.

  • News illusion: Plane crashes. A flood is destroying a city. A volcano is about to erupt. This is what news covers – blurbs of tragic events that are only negatively influencing your mood. The news illusion concept explains that we falsely believe that media is good for us. That what we see on TV and hear on the radio is helping us live a better life. In reality, the opposite happens. We start to feel worse. We start to imagine that the world is a dangerous place. Instead of embracing short snippets of information that will be irrelevant 24 hours later, bury yourself in books.
  • Salience effect: We tend to focus on the most obvious things in a situation. If a book is successful, we might say that it’s thanks to the marvelous cover. If you hear about a car crash and recently there was also a report about drunk drivers, you’ll conclude that the new event was also caused by irresponsible drinking. We focus on the sensational news rather than digging deeper to grasp the whole picture.
  • In-group out-group bias: We think differently when we’re surrounded by others and when we are on our own. When in a group, we adopt the desires of the people forming the team. When we’re alone, we favor our own judgments based on our past experiences. Be careful when you’re surrounded by others. Don’t immediately agree with the desires of the formation. Pause and consider the options on your own.

“Prejudice and aversion are biological responses to anything foreign. Identifying with a group has been a survival strategy for hundreds of thousands of years. Not any longer. Identifying with a group distorts your view of the facts.” Rolf Dobelli

Lesson #3: We are Blind to What Does Not Exist

Taking into account factors that are not obvious is one of the trickiest parts of decision-making.

Take books for example.

Yes, these chunks of paper that are glued together and cost around 15 bucks.

You can read reviews. Watch tutorials even of people explaining what the book is all about but you don’t actually see what’s inside until you read the actual book. Your decision of whether to get the book is based on outside influence – the author’s credibility, the rating online, the cover, the highlighted quotes on the back of the book, the price even.

Or in other words, you make decisions based on what you see with your eyes, not on what’s the actual product all about. A lot of times, this can be deceiving.

  • Feature-positive effect: Product creators emphasize on the key components. Since they want to sell you stuff, they’ll most probably hide, or make hard to obtain, the actual benefits you’ll get. This is how marketing campaigns are made – by stressing on the best features and by adding disclaimers with tiny fonts.
  • Survivorship bias: By exposing ourselves to loud newly-rich founders shouting online that they “made it” under 3 months, we start to dream of our own villa-style life. But this is the wrong approach. Survivorship bias explains that we have a tendency to focus only on things that survived – big corporations, rich people, old buildings that are still holding. This way we fail to register all the things that didn’t survive – all the founders and the companies that bankrupted in just a few years. Before making a conclusion, quitting your job to start your own company, consider what didn’t endure.
  • The problem with averages: Averages are deceiving. For example, the average salary in the US is around $54,000. If 5 US citizens who get the statistical middle salary are in a room and Bill Gates enters, the average will immediately skyrocket. But does this mean that the other folks in the room are richer? Of course not. Or in other words, things are not evenly distributed. You should keep this in mind when making calculations.

“We have problems perceiving nonevents. We are blind to what does not exist. We realize if there is a war, but we do not appreciate the absence of war during peacetime. If we are healthy, we rarely think about being sick. Or, if we get off the plane in Cancún, we do not stop to notice that we did not crash. If we thought more frequently about absence, we might well be happier.” Rolf Dobelli

Lesson #4: Experts Are Rarely That Experienced

Rarely in life, or in a certain field, there is someone who knows everything. A know-it-all guru if you must.

But that’s not what we see online these days.

A thousand-of-followers online magnet shares something and immediately the crowd is convinced that this excerpt without a context will transform their existence – like a magic pill.

We unquestionably believe authority figures. We don’t dare to question their expertise. “They have it all figured out,” we tell ourselves. “What they say must be correct.”

But that’s rarely true on every occasion.

People simply link any problem to their field. As the author writes, “Surgeons want to solve almost every medical problem with a scalpel, even if their patients could be treated with less invasive methods.”

  • Déformation professionnelle: Mark Twain famously said, “If your only tool is a hammer, all your problems will be nails.” Don’t expect the best solution from an expert. Expect a solution based on their specific area of expertise. Based on their experience. Based on what they, themselves, know. It can be a good solution to your problem but don’t hope for the ultimate best solution. No one is a know-it-all guru.
  • Strategic misrepresentation: People lie in interviews. People will tell you what you want to hear to get the deal. Hell, people even lease sports cars to signal to others that they are successful. Everyone is trying to sound and look better than they really are. This is normal for us, humans. But this is something you need to consider when negotiating a deal.
  • Illusion of skill: Luck plays a bigger role than skill does. Even if you started and later sold a company for millions, this doesn’t mean that you have superpowers. People get lucky all the time and confuse it with abilities they don’t really possess. Maybe your last project was blessed by the gods, maybe your co-founder did most of the job. Even if it’s not true, don’t boast too much about your skills. Don’t imagine that everything you do turns into gold. Rather, focus on further improving your skill-set.

“Certain people make a living from their abilities, such as pilots, plumbers, and lawyers. In other areas, skill is necessary but not critical, as with entrepreneurs and leaders. Finally, chance is the deciding factor in a number of fields, such as in financial markets. Here, the illusion of skill pervades.” Rolf Dobelli

Lesson #5: What Not To Do Is More Important Than What To Do

A piece of rock. That’s what sculptors need to create a statue.

And how do they do it? By simply removing the excess mass of rock and leaving only the object they want to portray.

The same is true in any other field.

You probably don’t know how to build a rocket ship. How to start a presidential campaign. Or how to start a side hustle. But you most probably can figure out what not to do if you want to do these things (Not being a jerk online. Not putting wheels on the rocket. Not offering everything for free.)

Not doing things is much more valuable and a lot simpler to do.

Or as the author mentions in the book, “Thinking more clearly and acting more shrewdly means adopting Michelangelo’s method: Don’t focus on David. Instead, focus on everything that is not David and chisel it away. In our case: Eliminate all errors and better thinking will follow.”

The last thinking concept in the book promotes exactly this counterintuitive approach – via negativa. Or focus on not doing things in English.

For example, if you want to lose weight so you can feel comfortable around other people when you’re without your t-shirt on, it will be much easier to not do certain things at first: not eating junk food, not missing a workout, not filling your refrigerator with microwave food.

Instead of focusing so much on the things you must do, concentrate on not doing things that are undermining your own life.

“We cannot say what brings us success. We can pin down only what blocks or obliterates success. Eliminate the downside, the thinking errors, and the upside will take care of itself. This is all we need to know.” Rolf Dobelli

Actionable Notes:

  • Zeigarnik effect: To successfully run projects, even if you have more than one going on, you need to clear your head. The Zeigarnik effect explains that once we complete a task it gets erased from our memory. But while we’re on the task, we’re exhausted and worried. Listing what needs to get done can help. A good plan of action can be enough to keep your sanity and walk you through the steps without feeling overburdened. So, when facing a challenging project, outline the main things to do on a piece of paper or an app.
  • Via negativa: Adopt the via negativa approach and focus on things you shouldn’t do. Don’t spend so much time on social media if you want to be more productive. Don’t spend so much money online if you want to save money. Don’t make impulsive decisions when important situations require your attention. Outlining what not to do is pretty obvious and it’s a great starting point to improve yourself.
  • Pay attention to what’s not visible: Our eyes see only what we are focusing on. A lot of times not seeing important information that can be crucial for our future. To be a master decision-maker, you must consider all options. All possibilities – even the ones that are not so obvious and such that are invisible for the eye. “Think the unthinkable. Something unusual can be huge; we still may not see it.”
  • Doubt free stuff: Facebook is free to use. Twitter as well. But are these online tools really costing us zero dollars? They are surely not. Instead of putting our time into good use, we spend a couple of hours per day engaged in mindless scrolling. That’s the ugly side of reciprocity. Big corporations invite potential clients to free meals with the intention to win them over their side. Sites offer free ebooks in exchange for your email address. All these things are done to convince you that you should return the favor at some point. Therefore, when something is free, ask yourself, “What’s the hidden price?”
  • The future performance is important: When money and time are invested in a project, our rationality quickly fails when this project is not performing well. We hold tight to it and we tell ourselves: “I’ve put a lot of effort into this. I can’t quit now!” That’s why investors hold stocks that are underperforming for years and people stay in exhausted relationships for decades. In these situations, the prior effort shouldn’t be the guiding force. You should focus more on future performance. If there are no sights for improvement, move on to the next thing.

Commentary and My Personal Takeaway

Not a how-to book to an error-free life but still a very good classification of behavioral and cognitive errors.

By listing all the thinking errors under the sun the author wants to prepare us for unfortunate situations. To showcase what we can possibly do wrong and give us a different way to approach situations.

There are 99 mental models listed in this book. Each one of them is covered in two or three pages tops which makes the book an easy read.

Still, if you’re a fan of behavior patterns you’ll most probably find this book kind of boring. The author is simply listing the most common thinking concepts and reinforcing his points with already known (at least to people who are familiar with the ideas) examples.

If you’re new to this type of knowledge, though, you’ll most probably love it. The short chapters help you quickly advance and give you a sense of joy.

One more thing if you decide to get the book: You don’t have to read the book from start to finish. Jump around. Read the thinking concepts you find most intriguing. The sections of the book aren’t connected to each other.

Key takeaway:

If you want to make improvements in your life, focusing on what not to do should be your go-to tactic. Want to have more money? Start spending less. You don’t necessarily have to start businesses or learn complicated investing strategies. Do, or should I say stop doing part of the things you’re doing now. This is the easiest way to rid yourself of undesired negative behaviors.

Notable Quotes:

“Our brains are designed to reproduce rather than search for the truth. In other words, we use our thoughts primarily to persuade. Whoever convinces others secures power and thus access to resources.” Rolf Dobelli

“Whether we like it or not, we are puppets of our emotions. We make complex decisions by consulting our feelings, not our thoughts. Against our best intentions, we substitute the question, “What do I think about this?” with “How do I feel about this?” So, smile! Your future depends on it.” Rolf Dobelli

“How do you curb envy? First, stop comparing yourself to others. Second, find your “circle of competence” and fill it on your own. Create a niche where you are the best. It doesn’t matter how small your area of mastery is. The main thing is that you are king of the castle.” Rolf Dobelli

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