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LESSON 1 · The Mental Models Playbook

When to Use Each Approach

First principles and analogical reasoning are complementary tools for different situations. Analogies fit when the domain is well-understood, the problem is common, and efficiency matters more than innovation.

The error is using analogies when first principles are needed — producing incremental improvement where breakthrough is possible. The key skill is recognizing which situations demand breaking down to fundamentals and which benefit from proven precedent.