In problem analysis, how does one deduce from a conclusion back to the most fundamental facts?

Hello, this is quite an interesting question, and it's a method we often unconsciously use in our daily lives. To peel back a "conclusion" layer by layer until you see the innermost "fact," my personal favorite simple and direct method is what many call "Continuous Questioning" or "The Five Whys."

Don't let the academic-sounding name fool you; it's as simple as a child asking questions.

Let me give you a very simple real-life example, and you'll understand.

The conclusion is: My car won't start.

Alright, let's work backward:

• First Why: Why won't the car start?

  • Answer: Because the battery is dead. (This is a preliminary fact, but not the most fundamental one.)

• Second Why: Why is the battery dead?

  • Answer: Because I forgot to turn off the headlights last night. (This might be a reason, but we need to confirm. If it was just forgotten headlights, it's an accidental event. But what if it wasn't? Let's assume after checking, the headlights were off, then we need to keep asking.)
  • Revised Answer: Oh, I checked, it wasn't the headlights. It might be because the alternator is broken and can't charge the battery. (This is a deeper fact.)

• Third Why: Why is the alternator broken?

  • Answer: The mechanic said it reached the end of its lifespan and was too worn out. (This is yet another deeper fact.)

• Fourth Why: Why did it wear out so quickly? (Or, why did it reach the end of its lifespan so fast?)

  • Answer: Because when I replaced it last time, to save money, I bought a cheap aftermarket part that wasn't very good quality. (This is already close to the essence of the problem.)

• Fifth Why: Why did you buy a cheap part to save money at that time?

  • Answer: Because I thought it wasn't important, as long as it worked, and I didn't consider the long-term risks and costs. (This is the most fundamental fact; it's about your decision-making criteria and values.)

You see, throughout this entire process:

From the superficial conclusion "the car won't start," we gradually traced back to the root cause: "sacrificing long-term reliability for short-term savings."

If you only stopped at the first step, "the battery is dead," your solution would be to replace the battery, but you might encounter the same problem again after a while. Only when you push to the final step do you realize that what truly needs to be addressed is your own habit of "being penny-wise and pound-foolish" in decision-making.

So, to summarize the essence of this method in three steps:

1. Grab a "conclusion" or "common sense" that you take for granted.
2. Like a persistent debater, ask "Why is this so?" about that conclusion.
3. For the answer you get, continue to ask "And why is that so?"... Repeat this cycle until you reach a point where you feel, "Oh, this is the fundamental reason; asking further would be meaningless." This "fundamental reason" will usually be a physical law, a mathematical axiom, a recognized human need, or a basic choice you've made.

In essence, this process is about dissecting a complex, packaged opinion, stripping away all the "I think," "I assumed," and "others say" embellishments, until you finally reveal the hardest, most undeniable "factual" core within.