First Principles Reasoning | Mindset Monday

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There are two types of reasoning: Reasoning by Analogy and Reasoning by First Principles.

With Reasoning by Analogy, you draw conclusions about one thing or activity because it is similar (at least in some respects) to another thing or activity.

For example:

  • Stars are very hot.
  • The sun is a star.
  • Therefore, the sun is very hot.

Pretty straightforward, right?

But what about this example:

  • 400 people who ate red meat regularly had heart attacks.
  • I eat red meat regularly.
  • Therefore, I’m very likely to have a heart attack.

Not so straightforward.

Which brings us to Reasoning by First Principles.

As Aristotle wrote, “In every systematic inquiry where there are first principles, or causes, or elements, knowledge and science result from acquiring knowledge of these; for we think we know something just in case we acquire knowledge of the primary causes, the primary first principles, all the way to the elements. It is clear, then, that in the science of nature as elsewhere, we should try first to determine questions about the first principles.” 

In other words:

  • Define your assumptions (and realize they are assumptions, not necessarily truths).
  • Check the premises of those assumptions.
  • Identify and uncover the truths and evidence.

So, to use our previous example: Let’s say you read on Facebook about a study in which 400 people who ate read meat had heart attacks.

Your assumption is that people who eat red meat are more likely to have heart attacks.

Let’s check the premises of this assumption:

  • Why do you think this?
  • Because you read it in a magazine? Which magazine?
  • Who conducted the study?
  • Who paid for the study?
  • What type of people were studied?
  • What else did those people consume in their diet?
  • Were those people physically active?

The list of questions goes on and  on. 

The bottom line is that, instead of taking the claim at face value, you recognized it as an assumption (not fact), and then you asked simple, yet key, questions to uncover evidence and truth.

In a recent interview with Kevin . Rose, Elon Musk revealed how he uses First Principles Reasoning in his decision-making process. 

“Somebody could say, ‘Battery packs are really expensive and that’s just the way they will always be. Historically, it has cost $600 per kilowatt hour.  It’s not going to be much better than that in the future,’” said Musk.

“With first principles,” explained, “You say, ‘what are the material constituents of the batteries? What is the stock market value of the material constituents? It’s got cobalt, nickel, aluminum, carbon, some polymers for separation and a seal can. Break that down on a material basis and say, ‘If we bought that on the London Metal Exchange what would each of those things cost?’

“It’s like $80 per kilowatt hour. So clearly you just need to think of clever ways to take those materials and combine them into the shape of a battery cell and you can have batteries that are much, much cheaper than anyone realizes.”

Instead of taking the assumption that the battery packs were too expensive, Musk peeled the onion to uncover the first principles, and reasoned a different, less expensive way, to meet his challenge.

We can also use First Principles Reasoning in our regular efforts to be more productive and create a better lifestyle.

For example, if your assumption is, “I’m too busy to exercise and get in shape,” we can start asking questions to uncover the truth:

  • Is exercise the only equation in terms of our health and fitness?
  • Wait, 80% of our body composition is determined by what we eat — so I can make a big change in my health simply through my nutrition?
  • Do I need an hour each day to exercise or could I do 15-minute high-intensity interval training workouts three times a week to get in shape?
  • Have I kept a time log to really audit how productively I’m spending my time each day?

Again, the questions could go on and on…but in any challenge we face, we can empower ourselves by recognizing assumptions versus truths.

Reasoning by Analogy isn’t always faulty. But Reasoning by First Principles is always more effective.


Want to learn how First Principles Reasoning can help turn you into a Productivity Superhero?

Learn more about our upcoming Productivity Superhero Accelerator

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