The first principles approach for problem solving that Elon Musk uses is an awesome way to find unconventional solutions to all kinds of problems. However this type of thinking does not come naturally to most people.
There are numerous mental barriers that prevent people from thinking in first principles. These barriers can be overcome with certain techniques, such as the generic parts technique and also by asking lots of questions. The hardest part of this entire process, though, is the application.
How can you take this knowledge and these techniques and apply them in practice? How can you make first principles thinking a part of your life?
In Part 2, we learned how to think in first principles. In this part, we will learn how to use that thinking in order to solve real-life problems. Here we go from theory to application.
Concrete examples from history
“Eureka! Eureka!” These legendary words were shouted by Archimedes, the Ancient Greek inventor, as he ran naked through the streets of Syracuse. This word can be roughly translated as “I have found it!” and since that time has become a synonym of discovery.
Archimedes was a really clever guy and discovered a lot of cool and practical stuff, but his legend was solidified by this one famous incident. The story that precedes this is the perfect example of using first principles thinking to come up with solutions to problems (and it even includes discovering some first principles themselves!).
King Hiero II of Syracuse wanted a golden crown to be made and assigned the work to a local goldsmith. When the goldsmith came back with the finished product, King Hiero suspected that the crown was not all gold and instead that the goldsmith had sneaked in some silver. However how to prove this little hunch?
Luckily, the King had Archimedes loitering around his city and so assigned the problem to him. Archimedes had to determine whether the crown was pure gold or it also included silver, without damaging it. This was almost an impossible problem and no one else in the kingdom had been able to come up with a solution.
This problem was initially also hard for Archimedes himself. He kept pondering it in his mind, but just couldn’t get around to figuring out a method to solve this little conundrum.
That’s where the story gets interesting. Archimedes was a cleanly fellow and one day was getting ready for his bath. He filled up the bath almost to the top with water, stripped down and then got in. As soon as he got into the bath, the water overflowed and spilled over the edge.
Archimedes noticed that as he got into the bath, the level of the water rose. This is what sparked the lighting bolt of discovery. He had discovered a first principle!
He summarized this principle in one of his works “On Floating Bodies”:
“Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.“
This is the first principle that Archimedes needed in order to solve the problem. If he submerged the crown in water, the crown would displace an amount of water equal to its volume. Archimedes could then use this fact to test whether the crown contained silver. If it did, then the crown would be less dense.
There is some discussion on the exact method that he used, but no matter the exact steps, it is a great example of coming up with first principles and then using them to solve a problem.
And yes, the goldsmith was a sneaky, dishonest dude and Archimedes proved it.