First principles: This is a mental model used by Elon Musk to understand complicated problems by breaking it down to its bare essentials and stripping off everything until the fundamental truth remains, thus removing any associated assumptions. It is similar to how software engineers think, by breaking down a big problem into many tiny ones. When you start breaking things down, you can start to see the fallacies associated with it. It is a questioning exercise.
Here is an excerpt from Farnam street:
First principles thinking is one of the best ways to reverse-engineer complicated situations and unleash creative possibility. Sometimes called reasoning from first principles, it’s a tool to help clarify complicated problems by separating the underlying ideas or facts from any assumptions based on them. What remains are the essentials. If you know the first principles of something, you can build the rest of your knowledge around them to produce something new.
I’ve been using it at work since the past few weeks to understand client needs. Typically, a client would request us for a feature that they might have come across on social media or competitors. Most of this request stems out of the Fear Of Missing Out (FOMO). Just because someone else has it we want it, without questioning if its the right for us.
Using First Principles thinking you can break down the requested feature into the principles of why that particular feature is successful. Is it because of its utility? Or is it a gimmick to go viral?
I use it while I’m learning about the company that I would potentially invest in. I ask questions like what why does this company exist? what are its main products? how are the products built? Do they have something that others don’t, that makes these products possible? What is the fundamental thing about this company that separates it from its competitors? Is it the management or userbase or something else?
Here is the video from the man himself, Elon Musk, explaining how to reason from First Principles.