Richard Feynman’s Principles of Scientific Thinking

Richard Feynman (1918-1988) is regarded as a hero and an inspiration, not only by many of his contemporaries but also by many of the smartest scientists alive today. Few people have made an impression on generations of curious intellectuals like the brilliant American theoretical physicist.

Along with Carl Sagan, Feynman is widely regarded as one of the best science communicators of the 20th century.

As a child, he didn't utter a word until 3. When he finally did get a handle on language, his friends said he "spoke like a bum." As a student, his notebooks were riddled with spelling errors.

In high school, a test revealed his IQ to be around 125 — higher than average but much lower than what you would expect of someone destined for physics greatness. It's likely, however, that the test emphasised his weak area: verbal ability. Feynman’s dominant strength was mathematics.

During the period that most of us were still struggling with Pythagoras’s theorem, the 15-year-old Feynman taught himself trigonometry, advanced algebra, and both differential and integral calculus. At 21, he obtained the highest scores ever recorded on the math/physics portions of the Princeton admission exams, while scoring poorly in (you guessed it) the English portion.

Of course, a little bad grammar wasn’t going to stop the insatiably curious physics professor from bringing his love of science, storytelling and bongo drums to the world’s attention. Despite a distinguished career, which included a Nobel Prize in 1965 for his work on quantum electrodynamics, Feynman is best remembered for his collection of anecdotes, including “Surely You’re Joking, Mr. Feynman!” (1985), his famed introductory physics lectures, and many enthralling video interviews that are easy to find online.

It is somewhat ironic that Feynman was ultimately known for his genius communication given his early start; however, there was no denying his ability to communicate complex ideas and transmit his enthusiasm in written word and over film.

In the list below, I have tried to capture the essence of Feynman’s world-view in statements that bear out recurring or underlying “first principles” that seem to permeate his work, and thus presumably, underlie his thinking. Many of these principles have been hugely influential in my own life. In fact, I am not able to bring to mind another scientist with a more incisive package of points for thinking clearly and rationally about the world. If you know of one, please let me know.

The Feynman Principles

• "The first principle is that you must not fool yourself, and you are the easiest person to fool."
• "Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, but none absolutely certain."
• "Permit us to question — to doubt — to not be sure."
• "Have no respect whatsoever for authority; forget who said it and instead look what he starts with, where he ends up, and ask yourself, 'Is it reasonable?'"
• "There is one feature I notice that is generally missing in cargo cult science (junk science) … It's a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty."
• "If you're doing an experiment, you should report everything that you think might make it invalid — not only what you think is right about it."
• "Scientific knowledge is an enabling power to do either good or bad — but it does not carry instructions on how to use it."
• "If we suppress all discussion, all criticism, proclaiming 'This is the answer, my friends; man is saved!' we will doom humanity for a long time to the chains of authority, confined to the limits of our present imagination."
• "We make no apologies for making these excursions into other fields, because the separation of fields, as we have emphasised, is merely a human convenience, and an unnatural thing. Nature is not interested in our separations, and many of the interesting phenomena bridge the gaps between fields."
• "Mathematics is not just a language. Mathematics is a language plus reasoning. It's like a language plus logic. Mathematics is a tool for reasoning."
• "I learned very early the difference between knowing the name of something and knowing something."
• "The real problem in speech is not precise language. The problem is clear language."
• "The only way to have real success in science, the field I’m familiar with, is to describe the evidence very carefully without regard to the way you feel it should be."
• "And therefore when we go to investigate we shouldn’t pre-decide what it is we are trying to do except to find out more about it."
• "The exception tests the rule."
• "That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong."

— Richard Feynman, theoretical physicist, scientist, teacher, raconteur and drummer

Bonus Video: 10 Times Richard Feynman Blew Our Minds