[pencilcheck]

Reasoning from analogy is the wrong way of saying what people have in mind when they provide examples to explain what it is. To me, it sound more like reasoning form what already works. In most examples I have seen, it is mostly about solving a problem using existing solutions/packages available and add your own flavor to it. That's why the "analogy" thinking because that's how the idea is presented, people pitch the idea using other's solutions. But what Elon Musk is different from others is that his thinking is stemming from scientific research more than you think it is. It is asking about the right question by digging deep into the core of the problem until you cannot dig any further. For example, in Elon Musk's example of battery, you first start with a goal: how to build an electric cars that is cost effective. You break the goals down into smaller problems, and you could recognize that battery is the biggest contributing factor in providing the solution to this goal, then you ask, why is the cost of battery so high yet it yield so little? Then you break the problem down into further smaller problems such as the cost for each component that comprised the battery, then you keep reasoning from there until you can find a ground where you can start reasoning back up. Personally I think the name "First principle" is also misleading since it is not mainly about principles, but more about asking the right questions.