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How to Remember What You Read

It happens all the time. You read an amazing book, one so packed with wisdom that you think it’s going to change your life forever. Then…it doesn’t. Why? Because when you’re finally in a situation where you could use its insights, you’ve completely forgotten them. Time is our most valuable resource, so we shouldn’t waste it. The investment we make in reading should have a positive, lasting impact on our lives.

Consuming information is not the same as acquiring knowledge. No idea could be further from the truth.

Learning means being able to use new information. The basic process of learning consists of reflection and feedback. We learn facts and concepts through reflecting on experience—our own or others’. If you read something and you don’t make time to think about what you’ve read, you won’t be able to use any of the wisdom you’ve been exposed to.

One of the reasons that we read books is because they offer a rich tapestry of details, allowing us to see the world of the author and go on their journey with them. Our brains can learn not only the author’s ideas but also when their conclusions about how to live are likely to work and when they are likely to fail (thanks to the vast amount of details that authors share about their experiences and thought processes).

But if you only remember six things after reading this article, it should be the following truths about reading:

  1. Quality matters more than quantity. If you read one book a month but fully appreciate and absorb it, you’ll be better off than someone who skims half the library without paying attention.
  2. Speed-reading is bullshit. Getting the rough gist and absorbing the lessons are two different things. Confuse them at your peril.
  3. Book summary services miss the point. A lot of companies charge ridiculous prices for access to vague summaries bearing only the faintest resemblance to anything in the book. Summaries can be a useful jumping-off point to explore your curiosity, but you cannot learn from them the way you can from the original text.*
  4. Fancy apps and tools are not needed. A notebook, index cards, and a pen will do just fine.
  5. We shouldn’t read stuff we find boring. Life is far too short.
  6. Finishing the book is optional. You should start a lot of books and only finish a few of them.

* (By the way, the book summaries we write for Farnam Street members are definitely not in the same class as the standard fare. We make a significant time investment in each one, including reading the book several times and doing background research on the author, context, and content. And we still don’t pretend they’re as valuable as reading the book!)

In this article, we’ll explore multiple strategies for getting more out of what you read. You don’t need to use all these strategies for every book. Using just a couple of them, whether you’re trying to learn a new philosophy or reading a work of fiction, can help you retain more and make deeper connections.

What you read can give you access to untold knowledge. But how you read changes the trajectory of your life.

Sections:

1) Active reading

    • Choose great books
    • Get some context
    • Know your why
    • Intelligently skim
    • Match your book to your environment

2) Remembering what you read

    • Take notes
    • Stay focused
    • Mark up the book
    • Make mental links
    • Quit books

3) Now what?

    • Apply what you’ve learned
    • Make your notes searchable
    • Reread

***

Active reading

“Every time I read a great book I felt I was reading a kind of map, a treasure map, and the treasure I was being directed to was in actual fact myself. But each map was incomplete, and I would only locate the treasure if I read all the books, and so the process of finding my best self was an endless quest. And books themselves seemed to reflect this idea. Which is why the plot of every book ever can be boiled down to ‘someone is looking for something.’” —Matt Haig, Reasons to Stay Alive

Now, if you’re only reading for fun, or if you don’t want to remember what you read, this article doesn’t apply. Sometimes reading is entertainment, and that’s wonderful. But if you want to get some valuable knowledge out of a book, the first step to getting more out of what you read is being active. So what is active reading?

Active reading is thoughtfully engaging with a book at all steps in the reading process. From deciding to read right through to reflection afterwards, you have a plan for how you are going to ingest and learn what’s in the book.

Books don’t enter our lives against a blank slate. Each time we pick up a book, the content has to compete with what we already think we know. Making room for the book, and the potential wisdom it contains, requires you to question and reflect as you read.

For example, you might ask yourself:

  • How does the book relate to topics you’re already familiar with?
  • What about the book challenges you?
  • What are your preconceived notions about its subject, and how can you put them aside?

Active reading helps you make connections within your latticework of mental models. Connections help retention.

Think back to the books you studied in school, if you did. Despite the passage of time, many people remember a surprising amount about them. Even if the details are fuzzy, we might at least be able to recall the basic plots, main characters, notable themes, and motifs. Why? Well for one, we probably didn’t just passively read those books. We were forced to actively read them, perhaps complete with class discussions where we took turns reading parts aloud, acted out scenes, or maybe even watched film adaptations. No matter how long it has been since we set foot in a classroom, many of us probably remember Animal Farm.

Your first goal when reading is to not be a passive consumer of information. You want to get better, learn something, and develop your critical thinking skills. If you had a good English teacher in school, you will have already seen this in action.

To get the most out of each book we read, it is vital we know how to record, reflect on, and put into action our conclusions.

A lot of success in reading boils down to preparation. What you do before you read matters more than you think. Here are five strategies to help you plan and get in the active reading frame of mind.

Choose Great Books

“Think before you speak. Read before you think.” —Fran Lebowitz

There are no rules when it comes to choosing books. We don’t have to read bestsellers, or classics, or books everyone else raves about. This isn’t school and there are no required reading lists. In fact, there’s an advantage to be gained from reading things other people are not reading, because you will gain knowledge and insights that not everyone else has. Focus on some combination of books that: 1) stand the test of time; 2) pique your interest; or 3) challenge you.

The more interesting and relevant we find a book, the more likely we are to remember its contents in the future. For older books or those that have been translated, check which version is considered to be the best.

Get some context

A good place to start getting context is by doing some preliminary research on the book. Some books—for example, A Confederacy of Dunces by John Kennedy Toole and Paradise by Toni Morrison—have a richer meaning once we know a bit about the life of the author and the place and time in which the novel was set.

For older books, try to understand the historical context. For books written in an unfamiliar country, try to understand the cultural context. Some helpful questions to ask include the following:

  • Why did the author write this?
  • What is their background?
  • What else have they written?
  • Where was it written? Was there anything interesting about the writing process?
  • What was the political, economic, and cultural situation at the time of writing?
  • Has the book been translated or reprinted?
  • Did any important events—a war, an economic depression, a change of leadership, the emergence of new technology—happen during the writing of the book?
  • What was happening in the world during the time the novel is set? This is particularly useful to ask when it comes to fiction.

You don’t need to do this, but if you want to get a lot out of a book it will be a major boost.

Know your why

What are you reading this book for? Entertainment? To understand something or someone you don’t know? To get better at your job? To improve your health? To learn a skill? To help build a business?

You have to have some idea of what you want to get from the book. If you don’t read with intention, what you read will never stick. If you are looking for business insights, read for that.

Periodically ask yourself questions like: What can I learn from this story? What in this book parallels or pertains to my own challenges? What are the differences? How might I apply some of the insights I’m picking up?

Intelligently skim

Before starting to read a book (particularly nonfiction), skim through the index, contents page, preface, and inside the jacket to get an idea of the subject matter. (This article on how to read a book is an introduction to more effective skimming.) Use this information to situate your expectations and refine what you are looking for as you read.

The bibliography can also indicate the tone and scope of a book. Authors often read hundreds of books for each one they write, so a well-researched book should have a bibliography full of interesting texts. After you’ve read the book, peruse the bibliography again and make a note of any books you want to read next.

Match the book to your environment

Although it’s not always practical, matching books to our location and circumstances can be powerful. Books will have a greater resonance as they become part of an experience rather than just supplementing it.

When choosing books, take a look at your own situation and decide on genres or authors that might help you overcome any current challenges or give you a fresh perspective. Whatever your state of affairs, someone has been in the same place. Someone has felt the same feelings and thought the same thoughts and written about it. Someone can offer you new and useful ideas for navigating your situation. It’s up to you to find them.

If we were doctors, we’d prescribe books. They can be powerful and healing.

***

Remembering what you read

“The things you’re looking for, Montag, are in the world, but the only way the average chap will ever see ninety-nine percent of them is in a book.” —Ray Bradbury, Fahrenheit 451

Now that you’re actively reading, you’re engaging on a deeper level with the book. You are making connections to your own life, seeing new opportunities and possibilities. The next step is making sure you remember what’s important. Even the most diligent of us get caught up in the busyness of life, and we thus lose those still-fragile connections we make while reading. But we can help with that.

You’ll remember more of what you read if you do the following five things while you’re reading.

Takes notes

Making notes is an important foundation for reflecting and integrating what you read into your mind.

The best technique for notetaking is whichever one works for you and is easy to stick to. While there are hundreds of systems on the internet, you need to take one of them and adapt it until you have your own system. Some people prefer to record notes on index cards or in a commonplace book; others prefer a digital system. Notes are especially useful if you write on a regular basis, although everyone (not just writers) can benefit from making them.

In How to Take Smart Notes, Sönke Ahrens suggests a way of approaching notetaking to make the books you read a lasting part of your thinking. If you’ve never really done any notetaking that was effective, his book is a great place to start. But wherever you begin, you must make a system your own depending on how you work and what you like to read. Although How to Take Smart Notes focuses on nonfiction and assumes that fiction writers (and readers) have no need of notes, don’t let that stop you if you are researching a time period in which to set a novel or you’re trying to learn story structure and style from the great novelists. Adapt your notetaking system to suit your goals.

Over the years, we tested a lot of different approaches to note-taking and even created our own that we use every day called the Blank Sheet Method. Here is how it works.

  1. Before you start reading a new book, take out a blank sheet of paper. Write down what you know about the book/subject you’re about to read — a mind map if you will.
  2. After you finish a reading session, spend a few minutes adding to the map with a different color.
  3. Before you start your next reading session, review the page.
  4. When you’re done reading, put these ‘blank sheets’ into a binder that you periodically review.

The blank sheet method is effective because it primes your brain and shows you what you’re learning. When you first start with a blank sheet, you’re forced to search your memory and put on paper what you know (or what you think you know) about a subject. As you read, you literally see your knowledge grow. If you don’t know anything about a book or subject going in, don’t worry. You’ll be able to borrow the author’s scaffolding to get you started. Reviewing your ‘blank sheet’ before your next reading session not only recalls the scaffolding and key ideas but improves your memory and connects ideas. When you’re done the book put the page into a binder. Review the binder every few months. This is essential for establishing deep fluency and connecting ideas across disciplines.

Another effective technique is to start your notetaking by writing a short summary of each chapter and transcribing any meaningful passages or phrases. If you are unsure how to simplify your thoughts, imagine that someone has tapped you on the shoulder and asked you to explain the chapter you just finished reading. They have never read this book and lack any idea of the subject matter. How would you explain it to them?

As you are reading a book, write your chapter summary right at the end of the chapter. If your reading session is over, this helps synthesize what you just read. When you pick up the book tomorrow, start by reading the previous two chapter summaries to help prime your mind to where you are in the book.

Stay focused

Decide that for the time you will be reading, you will focus on the book and nothing else. No quick Twitter checks. No emails. No cell phone. No TV. No staring into midair. Understanding and absorbing a book requires deep focus, especially if the subject matter is dense or complex. Remember, we are aiming for active reading. Active reading requires focus and the ability to engage with the words on the page.

Referring to the time before the internet, Nicholas Carr writes in The Shallows: “In the quiet spaces opened up by the prolonged, undistracted reading of a book, people made their own associations, drew their own inferences and analogies, fostered their own ideas. They thought deeply as they read deeply.

When you’re looking for results, for some tangible change to come out of reading a book, you need to engage with it as you’re reading it. And that requires focus.

If you’re struggling to stay focused on a particularly difficult or lengthy book, decide to read a mere 25 pages of it a day. It takes only a few minutes to nibble away at a challenging text. Completing a long book in this manner might take months, but at least you will have read it without getting overwhelmed or bored.

Mark up the book

Most of us were taught as children to treat books as something sacred—no folding the page corners, and no writing in the margins, ever. However, if you want to remember what you read and you have the means to do so, forget about keeping books pristine.

Go crazy with marginalia. The more you write, the more active your mind will be while reading. If you can’t mark up the book, do it on paper and note the page numbers.

Jot down connections and tangential thoughts, underline key passages, and make a habit of building a dialogue with the author(s). Some people recommend making your own index of key pages or using abbreviations.

The first time you write in a book can be unnerving, but in the long term, it leads to a rich understanding and a sense of connection with the author.

Make mental links

Books do not exist in a vacuum. Every concept or fact can be linked to countless others. Making an effort to form our own links is a fruitful way to better remember what we read.

Building vivid mental pictures is one of the most effective techniques for remembering anything, not least what we read. When you come across an important passage or concept, pause and visualize it. Make the picture as salient and distinctive as possible by connecting it to other ideas already in your brain.

Another way of building links is to hang everything on a latticework of mental models. Having a framework of deliberately constructed concepts enables us to better understand and synthesize books by allowing us to make connections to what we already know. Knowledge sticks in our memories easier if it attaches to something we already understand.

Using models while reading can also help you get more out of the book. Here are some examples of paths they might lead you down:

  • Confirmation bias: Which parts of this book am I ignoring? Does this book confirm my opinions? (Okay, but does it actually affirm your beliefs or are you just seeing what you want to see? If you cannot think of a single point in the book that you disagreed with, confirmation bias is likely distorting your reasoning.)
  • Bayesian updating: What opinions should I change in light of this book? How can I update my worldview using the information in it? Keep in mind the words of John Maynard Keynes: “When the facts change, I change my mind. What do you do, sir?”
  • Incentives: What motivates the characters or the author? What are they seeking? What is their purpose? Here’s how Kurt Vonnegut described the importance of incentives in books: “When I used to teach creative writing, I would tell the students to make their characters want something right away—even if it’s only a glass of water. Characters paralyzed by the meaninglessness of modern life still have to drink water from time to time.”
  • Availability bias: Are the books I have recently read affecting how I perceive this one? How are my immediate past experiences shaping my reading? Am I assigning undue importance to parts of this book because they are salient and memorable?
  • Social proof: How is social proof—the number of copies sold, bestseller status, the opinions of others—affecting my perception of this book? Is the author using social proof to manipulate readers? It is not unusual for authors to buy their way onto bestseller lists, providing social proof that then leads to substantial sales. As a result, mediocre books can end up becoming popular. It’s a classic case of the emperor having no clothes, which smart readers know to look out for.
  • Survivorship bias: Is this (nonfiction) book a representation of reality or is the author failing to account for base rates? Survivorship bias is abundant in business, self-help, and biographical books. A particular case of a successful individual or business might be held as the rule, rather than the exception.
  • Utility: If a book offers advice, does it have practical applications? At what point do diminishing returns set in?

Stop when bored

When it comes to reading, you don’t need to finish what you start. As a general rule, people who love reading never, ever finish a crappy book.

As Arthur Schopenhauer once wrote, “One can never read too little of bad, or too much of good books: bad books are intellectual poison; they destroy the mind.” Life is much too short to finish a bad book. You need to be ruthless and heartless. Don’t let sunk costs guilt you into wasting your time.

Author and librarian Nancy Pearl advocates the “Rule of 50.” This entails reading the first 50 pages of a book and then deciding if it is worth finishing. The Rule of 50 has an interesting feature: once you are over the age of 50, subtract your age from 100 and read that many pages. Pearl writes:

“And if, at the bottom of Page 50, all you are really interested in is who marries whom, or who the murderer is, then turn to the last page and find out. If it’s not on the last page, turn to the penultimate page, or the antepenultimate page, or however far back you have to go to discover what you want to know.…When you are 51 years of age or older, subtract your age from 100, and the resulting number (which, of course, gets smaller every year) is the number of pages you should read before you can guiltlessly give up on a book.…When you turn 100, you are authorized (by the Rule of 50) to judge a book by its cover.”

***

Now what?

So you’ve finished the book. Now what? How can you use what you have learned? Don’t just go away with a vague sense of “Oh yeah, I should totally do what that author says.” Take the time to make a plan and decide how to implement key lessons from the book.

Apply what you’ve learned

Reading alone is not enough. We have to contextualize the knowledge. When does it work? When doesn’t it work? Where can I apply it? What are the key variables? The list goes on. If you can take something you’ve read and apply it immediately, it will reinforce the learning and add context and meaning.

Another way to reinforce the learning is to apply the Feynman technique, named after the Nobel Prize-winning physicist Richard Feynman. You can think of it as an algorithm for guaranteed learning. There are four simple steps: choose a concept, teach it to someone unfamiliar with the subject, identify gaps in your understanding and go back to the source material, and review and simplify.

Teaching others is a powerful way to embed information in your mind. Upon completing a book, grab the nearest (willing) person and tell them about what you have learned. You’ll have to remove or explain the jargon, describe why this information has meaning, and walk them through the author’s logic. It sounds simple. After you try it the first time, you’ll realize it’s not easy.

If there is no one around who is interested, try writing a review where people are encouraged to comment and debate.

In order to think for yourself, you need to reflect on your views and see how they stand up to feedback.

Make your notes searchable

There are endless ways of organizing your notes—by book, by author, by topic, by the time of reading. It doesn’t matter which system you use as long as you will be able to find the notes in the future.

Having a catalogue of everything you learn from reading creates a priceless resource that can be consulted whenever you need an idea, want inspiration, or want to confirm a thought. Over the years, you will build up a bank of wisdom to refer to in times of crisis, uncertainty, or need. It is hard to convey quite how valuable this can prove to be.

As General Jim Mattis wrote: “Thanks to my reading, I have never been caught flat-footed by any situation, never at a loss for how any problem has been addressed (successfully or unsuccessfully) before. It doesn’t give me all the answers, but it lights what is often a dark path ahead.

The options for cataloguing your notes include the following:

  • A box of index cards, ideally organized by subject, topic, author, or time of reading. Index cards can be moved around.
  • A commonplace book (again, ideally organized by topic, author, or time of reading).
  • A digital system, such as Evernote, OneNote, or plain old Microsoft Word. Digital systems have the added benefit of being searchable, which can save a lot of time if you refer to your notes on a regular basis.

Schedule time to read and review these notes.

Reread (if you want to)

Read a lot. Expect something big, something exalting or deepening from a book. No book is worth reading that isn’t worth rereading.” —Susan Sontag

Skim a lot of books. Read a few. Immediately re-read the best ones twice. While rereading can seem like a waste of time because there are so many other books to read, this is a misunderstanding of the learning process. The best time to start rereading a great book is right after finishing. The goal is not to read as many books as possible. The goal is to gain as much wisdom as you can.

Rereading good books is of tremendous importance if we want to form lasting memories of the contents. Repetition is crucial for building memories.

Happy reading!

Why Math Class Is Boring—and What to Do About It

There are two types of people in the world: those who enjoyed mathematics class in school, and the other 98% of the population.

No other subject is associated with such widespread fear, confusion, and even outright hatred. No other subject is so often declared by children and adults alike to be something they “can’t do” because they lack an innate aptitude for it.

Math is portrayed as something you get or you don’t. Most of us sit in class feeling like we don’t.

But what if this weren’t the fault of the subject itself, but of the manner in which we teach it? What if the standard curriculum were a gross misrepresentation of the subject? What if it were possible to teach mathematics in a manner naturally incorporating the kinds of activities that appeal to children and learners of all ages?

All of those things are true, argues Paul Lockhart, a mathematician who chose to switch from teaching at top universities to inspiring grade-schoolers. In 2002, he penned “A Mathematician’s Lament,” a 25-page essay that was later expanded into a book.

In the essay, Lockhart declares that students who say their mathematics classes are stupid and boring are correct—though the subject itself is not. The problem is that our culture does not recognize that the true nature of math is art. So we teach it in a manner that would just as easily ruin any other art.

***

To illustrate the harms of the typical mathematical curriculum, Lockhart envisions what it would look like if we treated music or painting in the same dreary, arbitrary way.

What if music education was all about notation and theory, with listening or playing only open to those who somehow persevered until college?

“Since musicians are known to set down their ideas in the form of sheet music, these curious black dots and lines must constitute the “language of music.” It is imperative that students become fluent in this language if they are to attain any degree of musical competence; indeed, it would be ludicrous to expect a child to sing a song or play an instrument without having a thorough grounding in music notation and theory.

Playing and listening to music, let alone composing an original piece, are considered very advanced topics and are generally put off until college, and more often graduate school.”

And what if art students spent years studying paints and brushes, without ever getting to unleash their imaginations on a blank canvas?

“After class I spoke with the teacher. ‘So your students don’t actually do any painting?’ I asked.

‘Well, next year they take Pre-Paint-by-Numbers. That prepares them for the main Paint-by-Numbers sequence in high school. So they’ll get to use what they’ve learned here and apply it to real-life painting situations—dipping the brush into paint, wiping it off, stuff like that. Of course we track our students by ability. The really excellent painters—the ones who know their colors and brushes backwards and forwards—they get to the actual painting a little sooner, and some of them even take the Advanced Placement classes for college credit. But mostly we’re just trying to give these kids a good foundation in what painting is all about, so when they get out there in the real world and paint their kitchen they don’t make a total mess of it.'”

As laughable as we may find these vignettes, Lockhart considers them analogous to how we teach mathematics as something devoid of expression, exploration, or discovery.

Few who have spent countless hours on the equivalent of paint-by-numbers in the typical math class could understand that “there is nothing as dreamy and poetic, nothing as radical, subversive, and psychedelic, as mathematics.” Like other arts, its objective is the creation of patterns. The material mathematical patterns are made from is not paint or musical notes, however, but ideas.

Though we may use components of mathematics in practical fields such as engineering, the objective of the field itself isn’t anything practical. Above all, mathematicians strive to present ideas in the simplest form possible, which means dwelling in the realm of the imaginary.

In mathematics, Lockhart explains, there is no reality to get in your way. You can imagine a geometric shape with perfect edges, even though such a thing could never exist in the physical, three-dimensional world. Then you can ask questions of it and discover new things through experimentation with the imaginary. That process—“asking simple and elegant questions about our imaginary creations, and crafting satisfying and beautiful explanations”—is mathematics itself. What we learn in school is merely the end product.

We don’t teach the process of creating math. We teach only the steps to repeat someone else’s creation, without exploring how they got there—or why.

Lockhart compares what we teach in math class to “saying that Michelangelo created a beautiful sculpture, without letting me see it.” It’s hard to imagine describing one of Michelangelo’s sculptures solely in terms of the technical steps he took to produce it. And it seems impossible that one could teach sculpture without revealing that there is an art to it. Yet that is what we do with math all the time.

***

If school curriculums fundamentally misrepresent math, where does that misrepresentation come from? Lockhart views it as a self-perpetuating cultural deficiency.

Unlike other arts, we generally don’t celebrate the great works of mathematics and put them on display. Nor have they become all that integrated into our collective consciousness. It’s hard to change the feedback loops at play in education because “students learn about math from their teachers, and teachers learn about it from their teachers, so this lack of understanding and appreciation for mathematics in our culture replicates itself indefinitely.”

In schools, mathematics is treated as something absolute that needs no context, a fixed body of knowledge that ascends a defined ladder of complexity. There can be no criticism, experimentation, or further developments because everything is already known. Its ideas are presented without any indication that they might even be connected to a particular person or particular time. Lockhart writes:

“What other subject is routinely taught without any mention of its history, philosophy, thematic development, aesthetic criteria, and current status? What other subject shuns its primary sources—beautiful works of art by some of the most creative minds in history—in favor of third-rate textbook bastardizations?”

Efforts to engage students with mathematics often take the form of trying to make it relevant to their everyday lives or presenting problems as saccharine narratives. Once again, Lockhart doesn’t believe this would be a problem if students got to engage in the actual creative process: “We don’t need to bend over backwards to give mathematics relevance. It has relevance in the same way that any art does: that of being a meaningful human experience.” An escape from daily life is generally more appealing than an emphasis on it. Children would have as much fun playing with symbols as they have playing with paints.

Those whose mathematics teachers told them the subject was important because “you’re not going to have a calculator in your pocket at all times as an adult” have a good reason to feel like they wasted a lot of time learning arithmetic now that we all have smartphones. But we can imagine those who learn math because it’s entertaining would go out into the world seeing beautiful math patterns all over the place, and enjoying their lives more because of it.

***

If the existing form of mathematics education is all backward, what can we do to improve it? How can we teach and learn it as an art?

Lockhart does acknowledge that the teaching methods he proposes are unrealistic within the current educational system, where teachers get little control over their work and students need to learn the same content at the same time to pass exams. However, his methods can give us ideas for exploring the topic ourselves.

An education in the art of mathematics is above all a personal process of discovery. It requires tackling the sort of problems that speak to us at that particular point in time, not according to a preordained curriculum. If a new direction seems of interest, so be it. It requires space to take our time with exploration and an openness to making judgments (why should mathematics be immune to criticism?) All of this is far from ticking boxes:

The trouble is that math, like painting or poetry, is hard creative work. That makes it very difficult to teach. Mathematics is a slow, contemplative process. It takes time to produce a work of art, and it takes a skilled teacher to recognize one. Of course it’s easier to post a set of rules than to guide aspiring young artists, and it’s easier to write a VCR manual than to write an actual book with a point of view.

We should probably let go of the idea that doing math is about getting the right answer. Being creative is never about getting to a destination.

Above all, mathematics should be something we engage with because we find it to be a fun, challenging process capable of teaching us new ways to think or allowing us to express ourselves. The less practical utility or relevance to the rest of our lives it has, the more we’re truly engaging with it as an art.

How Description Leads to Understanding

Describing something with accuracy forces you to learn more about it. In this way, description can be a tool for learning.

Accurate description requires the following:

  1. Observation
  2. Curiosity about what you are witnessing
  3. Suspending assumptions about cause and effect

It can be difficult to stick with describing something completely and accurately. It’s hard to overcome the tendency to draw conclusions based on partial information or to leave assumptions unexplored.

***

Some systems, like the ecosystem that is the ocean, are complex. They have many moving parts that have multiple dependencies and interact in complicated ways. Trying to figure them out is daunting, and it can seem more sane to not bother trying—except that complex systems are everywhere. We live our lives as part of many of them, and addressing any global challenges involves understanding their many dimensions.

One way to begin understanding complex systems is by describing them in detail: mapping out their parts, their multiple interactions, and how they change through time. Complex systems are often complicated—that is, they have many moving parts that can be hard to identify and define. But the overriding feature of complex systems is that they cannot be managed from the top down. Complex systems display emergent properties and unpredictable adaptations that we cannot identify in advance. But far from being inaccessible, we can learn a lot about such systems by describing what we observe.

For example, Jane Jacobs’s comprehensive description of the interactions along city sidewalks in The Death and Life of Great American Cities led to insight about how cities actually work. Her work also emphasized the multidimensionality of city systems by demonstrating via description that attempting to manage a city from the top down would stifle its adaptive capabilities and negatively impact the city itself.

Another book that uses description to illuminate complicated and intricate relationships is The Sea Around Us by Rachel Carson. In it she chronicles events in the oceans, from the cycles of plankton growth to the movement of waves, in accessible, evocative descriptions. It’s no trouble to conjure up vivid images based on her words. But as the book progresses, her descriptions of the parts coalesce into an appreciation for how multidimensional the sea system is.

Carson’s descriptions come through multiple lenses. She describes the sea through the behavior of animals and volcanoes. She explores the sea by describing its vertical integration from the surface to the depths and the bottom. She looks at the oceans through the lenses of their currents and relationships to wind. In total the book describes the same entity, the seas that cover the majority of the earth’s surface, through thirteen different descriptive lenses. Although the parts are broken down into their basics, the comprehensive view that Carson employs allows the reader to easily grasp how complicated the sea system is.

None of the lenses she uses impart complete information. Trying to appreciate how interconnected the parts of the system are by looking at just her description of tides or minerals is impossible. It’s only when the lenses are combined that a complete picture of the ecosystem emerges.

The book demonstrates the value in description, even if you cannot conclude causation in the specifics you’re describing.

One noticeable omission from the book is the role of plate tectonics in the movement of the ocean floor and associated phenomena like volcanoes. Plate tectonic theory is a scientific baby and was not yet widely accepted when Carson updated her original text in 1961. But not knowing plate tectonic theory doesn’t undermine her descriptions of life at the bottom of the oceans, or the impact of volcanoes, or the changing shape of the undersea shelves that attach to the continents. Although the reader is invited to contemplate the why behind what she is describing, we are also encouraged to be in the moment, observing the ocean through Carson’s words.

***

The book is not an argument for a particular way of interacting with the sea. It doesn’t need to make one. Carson’s descriptions offer their own evidence of how trying to change or manage the sea system would be extremely difficult because they reveal the multitude of connections between various sea phenomena.

Describing the whole from so many different angles illuminates the complex. By chronicling microinteractions, such as those between areas of hot and cold water or high and low pressure, we can see how changes in one aspect produce cascading change. We also get a sense of the adaptability of the living organisms that live in the oceans, like being able to live in depths that have no light (and therefore no plants that rely on photosynthesis) and adjusting biochemistry to take advantage of seasonal variations in temperature that affect water weight and salt contents.

The reader walks away from the book appreciating the challenge in describing in detail something as complicated as the ocean ecosystem. The book is full of observations and short on judgments, an approach that encourages us to develop our own curiosity about the sea around us.

The Sea Around Us is the Farnam Street book club’s summer selection. Members get additional resource materials to help get the most out of this fascinating book. Learn more or join in.

Mirror Your Audience: Four Life Lessons From Performance Artist Marina Abramović

Imagine it is a Saturday. You are in New York and decide to go to the Museum of Modern Art. There is a special exhibit on called The Artist is Present. Performance artist Marina Abramovic is sitting in one of the galleries. You wait in line to sit across from her, noticing that hundreds of people are lined up for the experience. Anticipation slowly builds as your time gets closer.

From your spot in line, you can see her seated in a red dress. Across the table from her, people sit; some for mere moments, others for long stretches. You later learn that there is no limit on the length of time you can sit at the table across from her, but you are not allowed to touch or talk to her. As you are waiting in line, the experience is like looking at a living painting.

When it’s your turn and you take your seat across from her, your experience transforms and becomes part of the art itself.

Marina Abramovic performed The Artist is Present, sitting eight hours a day for three months in 2010. She trained for months to build the physical stamina to perform the piece, and in her memoir Walk Through Walls she comments on how the performance demonstrated the profound need for people to connect.

Originally from Belgrade, Abramovic began her art career in the 1960s, starting with traditional painting, before moving into performance pieces in the early 1970s. Many of her pieces are iconic, and she continues to work all over the world.

Here are some of her insights from her memoir that transcend performance art and speak to how we can move through life to achieve our goals.

On fear

It is incredible how fear is built into you, by your parents and others surrounding you.”

Human beings are afraid of very simple things: we fear suffering, we fear mortality. What I was doing in Rhythm 0—as in all my other performances—was staging these fears for the audience: using their energy to push my body as far as possible. In the process, I liberated myself from my fears. And as this happened, I became a mirror for the audience—if I could do it, they could do it too.

The relationship we have with fear can be one of the defining relationships of our life. Finding a way to accept and process our fears is an ongoing task that can be mastered by willingly exploring them.

For the first three months, I place each student at a table with a thousand pieces of white paper and a trash can underneath. Every day they have to sit at the table for several hours and write ideas. They put the ideas they like on the right side of the table; the ones they don’t like, they put in the trash. But we don’t throw out the trash. After three months, I only take the ideas from the trash can. I don’t even look at the ideas they liked. Because the trash can is a treasure trove of things they’re afraid to do.”

Part of dealing with fear is acknowledging it. Hiding fear in the garbage bin does us no good. When we confront what we are afraid to do, we find immense opportunities to develop and grow because we increase our options and adaptability. We both remove limits and teach ourselves how to handle a wider spectrum of fear-inducing situations in the future.

On finding your place

“All at once it occurred to me—why paint? Why should I limit myself to two dimensions when I could make out from anything at all: fire, water, the human body? Anything! There was something like a click in my mind—I realized that being an artist meant having immense freedom.”

We need to explore until we find our “clicks.” Limiting ourselves to convention might not be satisfactory. As Abramovic began to develop her performance art pieces, her physical self was at the center of her work. In most of her pieces, the audience was confronted with the idea of art as a living thing: not a painting on a wall, but a physical body.

“The essence of performance is that the audience and the performer make the piece together.”

In one of her pieces, people entered the gallery while she stood completely still, dressed in a blouse and pants. On a table in front of her were dozens of objects—things like cards, lipstick, pins, and even a gun. Over the next hours, the audience was invited to use any object to do whatever they wanted to Abramovic. Slowly at first, but with increasing momentum, they began to interact with her body. They moved her arms, put lipstick on her, put cards in her hand. One person stuck a pin into her. Only at the end of the night did security intervene when someone picked up the gun and prepared to shoot her.

It must have been an incredible experience.

The notion that an audience can participate in the creation of art as it is happening has been an important aspect of many of Abramovic’s performances. In the dynamic nature of performance art, Abramovic has found her medium to explore the nature of art itself.

“I had experienced absolute freedom—I had felt that my body was without boundaries, limitless; that pain didn’t matter, that nothing mattered at all—and it intoxicated me. I was drunk from the overwhelming energy that I’d received. That was the moment I knew that I had found my medium.”

Paying attention to our moments as we experience them helps us find our place. Abramovic writes often in her memoir about the success that came with being fully committed to her performances while they were happening. Her ability to move through physical pain in pursuit of artistic expression, and to communicate with her audience, stems in part from her knowing she was creating from a place of authenticity.

On art

“What is art? I feel that if we see art as something isolated, something holy and separate from everything, that means it’s not life. Art must be a part of life. Art has to belong to everybody.”

Another famous piece of hers was done in a gallery space, where she lived in front of the audience in three open rooms. Each room was a square box with one side removed. One was a living room, another one was a bedroom, and the final one was a bathroom. Abramovic did everything in front of the crowds who came into the gallery—sleep, meditate, shower, and use the toilet. One interpretation of the work is that by inviting the audience to watch her doing some of the mundane daily tasks that we all do, she provided a way for them to find the art in their own lives.

“This is a rule of performance: once you enter into this mental-physical construct you’ve devised, the rules are set, and that’s that—you’re the last one who can change them.”

Part of Abramovic’s success has stemmed from her fearlessness in using performance art to explore basic questions of humanity, as well as from her total respect for the medium. Her pieces are thoughtful, and no doubt leave a lasting impression on those who are able to watch and engage with them.

On the business of art

“It’s interesting with art. Some people have the ability—and the energy—not just to make the work, but to make sure it’s put in exactly the right place, at the right moment. Some artists realize they have to spend as much time as it took them to get an idea in finding the way to show it, and the infrastructure to support it. And some artists just don’t have that energy, and have to be taken care of, by art lovers or collectors or the gallery system.”

The business of creating and the business of selling one’s creations require different skills and temperaments that are not always found in the same person. When we know our capabilities, we can try to set ourselves up for success by knowing how and where to ask for help. All of us want our outputs to be recognized in some way. What we don’t often realize is that we have a part to play in getting that recognition to happen. We can’t expect everything to magically fall into place.

From the mid-1970s to the end of the decade, performance art caught on. . . . The originators of the medium were no longer young, and this work was very hard on the body. And the market, and art dealers especially, were putting increasing pressure on artists to make something to sell, because, after all, performance produced nothing marketable.”

Choices close some doors and open others. Having a personal definition of success is critical. We have to make sacrifices to achieve our goals, so we must be confident we are working toward our own idea of success and not someone else’s. Abramovic continues to do performance art, but she also became an art teacher and has partnered on numerous other art projects, including films. From her memoir, we learn that an insightful way of measuring our achievements is against what we believe gives life meaning.

The Method of Loci: Build Your Memory Palace

“When information goes ‘in one ear and out the other,’ it’s often because it doesn’t have anything to stick to.” —Joshua Foer

According to legend, the renowned Greek lyric poet Simonides of Ceos was dining at the home of a wealthy nobleman one night when he received word that two young men were waiting outside with a message for him. Simonides stepped outside—mere moments before the roof of the banquet hall caved in, killing everyone inside. The extent of the destruction was so great that the family and friends of the deceased guests despaired of being able to identify their bodies.

But Simonides found that if he pictured the spatial layout of the hall, he could mentally walk around it and recall the names of the guests seated in each place. In this way, he helped identify the unfortunate diners. From this experience, Simonides deduced that remembering factual information is easiest if we tie it to a physical location we are familiar with. As the great orator Cicero explained:

“He inferred that persons desiring to train this faculty must select localities and form mental images of the facts they wish to remember and store those images in the localities, with the result that the arrangement of the localities will preserve the order of the facts, and the images of the facts will designate the facts themselves, and we shall employ the localities and images respectively as a wax writing tablet and the letters written on it.

. . . It has been sagaciously discerned by Simonides or else discovered by some other person that the most complete pictures are formed in our minds of the things that have been conveyed to them and imprinted on them by the senses, but that the keenest of all our senses is the sense of sight, and that consequently perceptions received by the ears or by reflection can be most easily retained in the mind if they are also conveyed to our minds by the mediation of the eyes, with the result that things not seen and not lying in the field of visual discernment are earmarked by a sort of image and shape so that we keep hold of as it were by an act of sight things that we can scarcely embrace by an act of thought.”

Today we know this technique as the “method of loci” or “memory palace.” Here’s how constructing a memory palace can help you memorize information and recall it with ease.

Spatial memory

From the time we learn to walk, we start building up spatial memories—recollections of the layouts of physical spaces and their relationships to the objects in them. These memories tend to form fast and stick around for a long time.

The method of loci hijacks our innate aptitude for remembering physical spaces, using it to help us remember other kinds of information with greater ease.

Although it may seem as if people who manage unusual feats of memory have unusual innate capabilities, much of the available evidence suggests that isn’t the case. Instead, they tend to simply use innate capabilities in unusual, creative ways. In Moonwalking with Einstein, journalist Joshua Foer discovers this for himself while investigating memory championships. After contestants tell him anyone could do what they do with the right training, Foer sets his sights on the USA Memory Championship—and goes on to win.

Foer’s journey started by researching memory and its physical effects on the brain. Scientists had recently discovered that your brain is much like a muscle and that making it work could make it grow by creating new pathways at a cellular level.

Does that mean the brain of a “mental athlete” is different from that of a normal person? Not necessarily. Foer found research indicating memory specialists simply used different parts of their brains for recalling information. They converted it into a visual form and positioned it in a spatial location.

A memory palace is an ancient mnemonic device that leverages the way we find it easiest to recall information: spatially and visually.

You might have experienced the power of spatial memory if you’ve ever revisited a place where you experienced something unpleasant or sad. Minor details might have been enough to make you vividly remember the experience.

How to build a memory palace

Let’s look at an example to illustrate the concept.

Say your memory palace is your childhood home. Take a moment to conjure images and memories of that place. We are going to stick to the outside of the house. Mentally walk from the road to your front door, trying to remember as many details as possible.

Let’s imagine you want to remember to buy some steaks on the way home. Now put the steaks, exactly how they look in the grocery store, on your front porch.

Got it?

Okay, now let’s try to make the steaks into something more memorable. How about a cow sitting on your front porch—not like a cow would, but like a person would. Let’s make them exaggeratedly chewing, but we’ll make it bubblegum instead of grass. Now the cow is periodically blowing gigantic bubbles, so big that you’re worried they might pop. Maybe think about the strange smell of bubblegum and cow mixed together. What would the cow’s skin feel like? What would it feel like to have to pick bubblegum off of the cow’s face?

Four hours from now when you leave work to head home, you’ll remember you had to pick something up from the grocery store. When you take a trip to your memory palace, walk up the drive and gaze at your front step. What do you think you are more likely to remember? The packaged steaks that you see all the time? Or the gum-chewing cow we created?

Now, imagine you also need to remember to buy carrots and olive oil, so you place those in your memory palace too. As you step onto the front step, past the bubblegum blowing cow, you see the row of muddy shoes you recall usually being next to the front door. You picture each shoe being filled with soil, the leaves and orange tops of carrots growing in them just visible. Before you can press the doorbell, the door is opened by the cartoon character Olive Oyl, wearing a crown of olive branches. And so on.

If you’re trying to learn something more complex and important than a shopping list, it’s possible to keep repeating this process until you’ve constructed an incredibly detailed memory palace with hundreds of items. Or you might use multiple different locations for various purposes. You could also use a journey, such as your walk to work.

No matter what, you want to make your mental image engage with the location as much as possible and ideally involve multiple senses. Avoid placing multiple different items in parts of your memory palace that look too similar, such as identical dining room chairs.

The beauty of the memory palace technique is that it’s highly adaptable for remembering all kinds of information in whatever way feels easiest to you.

Remembering numbers

The memory palace is a great way to recall a variety of things, but you will still hit a hard ceiling, and that ceiling conflicts with the Herculean amount of numbers some memory competitors can remember. What’s the trick? It turns out that there is a whole different tool just for recalling numbers.

PAO: Person – Action – Object
In this system, every two-digit number from 00 to 99 is processed into a single image of a person performing an action on an object. Joshua Foer writes:

“The number 34 might be Frank Sinatra (a person) crooning (an action) into a microphone (an object). Likewise, 13 might be David Beckham kicking a soccer ball. The number 79 could be Superman flying with a cape. Any six-digit number, like say 34-13-79, can then be turned into a single image by combining the person from the first number with the action from the second and the object for the third – in this case, it would be Frank Sinatra kicking a cape.”

As you can see, this is still about storing very vivid and memorable images. We don’t know about you, but Frank Sinatra kicking a cape hasn’t come to our minds before. It becomes a very powerful tool when you realize that you can use your “stock images” as a sort of algorithm to generate a unique image for every number between 0 and 999,999.

How a memory palace works

When we’re learning something new, it requires less effort if we connect it to something we already know, such as a physical place. This is known as elaborative encoding. Once we need to remember the information, we can “walk” around the palace and “see” the various pieces.

The idea is to give your memories something to hang on to. We are pretty terrible at remembering things, especially when these memories float freely in our heads. But our spatial memory is actually pretty decent, and when we give our memories some needed structure, we provide that missing order and context.

For example, if you struggle to remember names, it can be helpful to link people you meet to names you already know. If you meet someone called Fred and your grandmother had a cat called Fred, you could connect the two. Creating a multisensory experience in your head is the other part of the trick. In this case, you could imagine the sound of Fred meowing loudly.

To further aid in recall, the method of loci is most effective if we take advantage of the fact that it’s easiest to remember memorable things. Memory specialists typically recommend mentally placing information within a physical space in ways that are weird and unusual. The stranger the image, the better.

Returning to the name example, it will probably stick better if you imagine Fred the person being chased by a giant version of Fred the cat, compared to just imagining them next to each other.

Cicero further explains:

“But these forms and bodies, unlike all the things that come under our view, require an abode, inasmuch as a material object without a locality is inconceivable. Consequently (in order that I may not be tedious on a subject that is well known and familiar) one must employ a large number of localities which must be clear and defined and at moderate intervals apart, and images that are effective and sharply outlined and distinctive, with the capacity of encountering and speedily penetrating the mind; the ability to use these will be supplied by practice, which engenders habit, and by marking off similar words with an inversion and alteration of their cases or a transference from species to genus, and by representing a whole concept by the image of a single word, on the system and method of a consummate painter distinguishing the positions of objects by modifying their shapes.”

The Roman rhetorician Quintilian also recommended the memory palace technique:

“Some have thought memory to be a mere gift of nature, and to nature, doubtless, it is chiefly owing. But it is strengthened, like all our other faculties, by exercise, and all the study of the orator of which we have been speaking is ineffectual unless the other departments of it be held together by memory as by an animating principle. All knowledge depends on memory, and we shall be taught to no purpose if whatever we hear escapes from us.

. . . when we return to places, after an absence of some time, we not only recognize them, but recollect also what we did in them. Persons whom we saw there, and sometimes even thoughts that passed within our minds, recur to our memory. Hence, in this case, as in many others, art has had its origin in experiment. People fix in their minds places of the greatest possible extent, diversified by considerable variety, such as a large house, for example, divided into many apartments. Whatever is remarkable in it is carefully impressed on the mind, so that the thought may run over every part of it without hesitation or delay. Indeed, it is of the first importance to be at no loss in recurring to any part, for ideas which are meant to excite other ideas ought to be in the highest degree certain.

They then distinguish what they have written, or treasured in their mind, by some symbol by which they may be reminded of it, a symbol which may either have reference to the subject in general, as navigation or warfare, or to some particular word, for if they forget, they may, by a hint from a single word, find their recollection revived . . . they place, as it were, their first thought under its symbol, in the vestibule, and the second in the hall, and then proceed round the courts, locating thoughts in due order, not only in chambers and porticoes, but on statues and other like objects. This being done, when the memory is to be tried, they begin to pass in review all these places from the commencement, demanding from each what they have confided to it, according as they are reminded by the symbol. Thus, however numerous are the particulars which they have to remember, they can, as they are connected each to each like a company of dancers hand to hand, make no mistake in joining the following to the preceding, if they only take due trouble to fix the whole in their minds.

What I have specified as being done with regard to a dwelling house may also be done with regard to public buildings, or a long road, or the walls of a city, or pictures, or we may even conceive imaginary places for ourselves.”

An important caveat is that the method of loci only helps you recall the specific information you’ve used it to encode. While you might find it easier to use the technique the more times you repeat it, you’re unlikely to see an overall improvement in your general memory.

Despite its limitations, constructing a memory palace is a fun and creative way to learn things you don’t want to write down (such as passwords or security question answers) or want to be able to call to mind on the fly (such as decision-making checklists). And if you’re someone who enjoys a challenge, it can be satisfying to see just how far you can extend your innate abilities.

***

The memory palace reminds us of the importance of being mindful and paying attention to life. Foer takes it further, arguing that when we look at it critically, memory is a huge component of almost every aspect of our lives:

“How we perceive the world and how we act in it are products of how and what we remember. We’re all just a bundle of habits shaped by our memories. And to the extent that we control our lives, we do so by gradually altering those habits, which is to say the networks of our memory. . . . Our ability to find humor in the world, to make connections between previously unconnected notions, to create new ideas, to share in a common culture: all these essentially human acts depend on memory. Now more than ever, as the role of memory in our culture erodes at a faster pace than ever before, we need to cultivate our ability to remember. Our memories make us who we are.”

We are a culmination of our experiences. How we process this information and encode it into something meaningful is intrinsically tied to our memory. Understanding how it works and how to use tools or tricks to make it better is a worthy endeavor.

The Precautionary Principle: Better Safe than Sorry?

Also known as the Precautionary Approach or Precautionary Action, the Precautionary Principle is a concept best summed up by the proverb “better safe than sorry” or the medical maxim to “first do no harm.”

While there is no single definition, it typically refers to acting to prevent harm by not doing anything that could have negative consequences, even if the possibility of those consequences is uncertain.

In this article, we will explore how the Precautionary Principle works, its strengths and drawbacks, the best way to use it, and how we can apply it in our own lives.

Guilty until proven innocent

Whenever we make even the smallest change within a complex system, we risk dramatic unintended consequences.

The interconnections and dependencies within systems make it almost impossible to predict outcomes—and seeing as they often require a reasonably precise set of conditions to function, our interventions can wreak havoc.

The Precautionary Principle reflects the reality of working with and within complex systems. It shifts the burden of proof from proving something was dangerous after the fact to proving it is safe before taking chances. It emphasizes waiting for more complete information before risking causing damage, especially if some of the possible impacts would be irreversible, hard to contain, or would affect people who didn’t choose to be involved.

The possibility of harm does not need to be specific to that particular circumstance; sometimes we can judge a category of actions as one that always requires precaution because we know it has a high risk of unintended consequences.

For example, invasive species (plants or animals that cause harm after being introduced into a new environment by humans) have repeatedly caused native species to become extinct. So it’s reasonable to exercise precaution and not introduce living things into new places without strong evidence it will be harmless.

Preventing risks and protecting resources

Best known for its use as a regulatory guideline in environmental law and public health, the Precautionary Principle originated with the German term “Vorsorgeprinzip” applied to regulations for preventing air pollution. Konrad Von Moltke, director of the Institute for European Environmental Policy, later translated it into English.

Seeing as the natural world is a highly complex system we have repeatedly disrupted in serious, permanent ways, the Precautionary Principle has become a guiding part of environmental policy in many countries.

For example, the Umweltbundesamt (German Environmental Protection Agency) explains that the Precautionary Principle has two core components in German environmental law today: preventing risks and protecting resources.

Preventing risks means legislators shouldn’t take actions where our knowledge of the potential for environmental damage is incomplete or uncertain but there is cause for concern. The burden of proof is on proving lack of harm, not on proving harm. Protecting resources means preserving things like water and soil in a form future generations can use.

To give another example, some countries evoke versions of the Precautionary Principle to justify bans on genetically modified foods—in some cases for good, in others until evidence of their safety is considered stronger. It is left to legislators to interpret and apply the Precautionary Principle within specific situations.

The flexibility of the Precautionary Principle is both a source of strength and a source of weakness. We live in a fast-moving world where regulation does not always keep up with innovation, meaning guidelines (as opposed to rules) can often prove useful.

Another reason the Precautionary Principle can be a practical addition to legislation is that science doesn’t necessarily move fast enough to protect us from potential risks, especially ones that shift harm elsewhere or take a long time to show up. For example, thousands of human-made substances are present in the food we eat, ranging from medications given to livestock to materials used in packaging. Proving that a new additive has health risks once it’s in the food supply could take decades because it’s incredibly difficult to isolate causative factors. So some regulators, including the Food and Drug Administration in America, require manufacturers to prove something is safe before it goes to market. This approach isn’t perfect, but it’s far safer than waiting to discover harm after we start eating something.

The Precautionary Principle forces us to ask a lot of difficult questions about the nature of risk, uncertainty, probability, the role of government, and ethics. It can also prompt us to question our intuitions surrounding the right decisions to make in certain situations.

When and how to use the Precautionary Principle

When handling risks, it is important to be aware of what we don’t or can’t know for sure. The Precautionary Principle is not intended to be a stifling justification for banning things—it’s a tool for handling particular kinds of uncertainty. Heuristics can guide us in making important decisions, but we still need to be flexible and treat each case as unique.

So how should we use the Precautionary Principle? Sven Ove Hansson suggests two requirements in How Extreme Is the Precautionary Principle? First, if there are competing priorities (beyond avoidance of harm), it should be combined with other decision-making principles. For example, the idea of “explore versus exploit” teaches us that we need to balance doubling down on existing options with trying out new ones. Second, the decision to take precautionary action should be based on the most up-to-date science, and there should be plans in place for how to update that decision if the science changes. That includes planning how often to revaluate the evidence and how to assess its quality.

When is it a good idea to use the Precautionary Principle? There are a few types of situations where it’s better to be safe rather than sorry if things are uncertain.

When the costs of waiting are low. As we’ve already seen, the Precautionary Principle is intended as a tool for handling uncertainty, rather than a justification for arbitrary bans. This means that if the safety of something is uncertain but the costs of waiting to learn more are low, it’s a good idea to use precaution.

When preserving optionality is a priority. The Precautionary Principle is most often evoked for potential risks that would cause irreversible, far-reaching, uncontainable harm. Seeing as we don’t know what the future holds, keeping our options open by avoiding limiting choices gives us the most flexibility later on. The Precautionary Principle preserves optionality by ensuring we don’t restrict the resources we have available further down the line or leave messes for our future selves to clean up.

When the potential costs of a risk are far greater than the cost of preventative action. If a potential risk would be devastating or even ruinous, and it’s possible to protect against it, precautionary action is key. Sometimes winning is just staying in the game—and sometimes staying in the game boils down to not letting anything wipe you out.

For example, in 1963 the Swiss government pledged to provide bunker spaces to all citizens in the event of a nuclear attack or disaster. The country still maintains a national system of thousands of warning sirens and distributes potassium iodide tablets (used to reduce the effects of radiation) to people living near nuclear plants in case of an accident. Given the potential effects of an incident on Switzerland (regardless of how likely it is), these precautionary actions are considered worthwhile.

When alternatives are available. If there are alternative courses of action we know to be safe, it’s a good idea to wait for more information before adopting a new risky one.

When not to use the Precautionary Principle

As the third criteria for using the Precautionary Principle usefully, Sven Ove Hansson recommends it not be used when the likelihood or scale of a potential risk is too low for precautionary action to have any benefit. For example, if one person per year dies from an allergic reaction to a guinea pig bite, it’s probably not worth banning pet guinea pigs. We can add a few more examples of situations where it’s generally not a good idea to use the Precautionary Principle.

When the tradeoffs are substantial and known. The whole point of the Precautionary Principle is to avoid harm. If we know for sure that not taking an action will cause more damage than taking it possibly could, it’s not a good idea to use precaution.

For example, following a 2011 accident at Fukushima, Japan shut down all nuclear power plants. Seeing as nuclear power is cheaper than fossil fuels, this resulted in a sharp increase in electricity prices in parts of the country. According to the authors of the paper Be Cautious with the Precautionary Principle, the resulting increase in mortality from people being unable to spend as much on heating was higher than the fatalities from the actual accident.

When the risks are known and priced in. We all have different levels of risk appetite and we make judgments about whether certain activities are worth the risks involved. When a risk is priced in, that means people are aware of it and voluntarily decide it is worthwhile—or even desirable.

For example, riskier investments tend to have higher potential returns. Although they might not make sense for someone who doesn’t want to risk losing any money, they do make sense for those who consider the potential gains worth the potential losses.

When only a zero-risk option would be satisfying. It’s impossible to completely avoid risks, so it doesn’t make much sense to exercise precaution with the expectation that a 100% safe option will appear.

When taking risks could strengthen us. As individuals, we can sometimes be overly risk averse and too cautious—to the point where it makes us fragile. Our ancestors had the best chance of surviving if they overreacted, rather than underreacted, to risks. But for many of us today, the biggest risk we face can be the stress caused by worrying too much about improbable dangers. We can end up fearing the kinds of risks, like social rejection, that are unavoidable and that tend to make us stronger if we embrace them as inevitable. Never taking any risks is generally a far worse idea than taking sensible ones.

***

We all face decisions every day that involve balancing risk. The Precautionary Principle is a tool that helps us determine when a particular choice is worth taking a gamble on, or when we need to sit tight and collect more information.