Mental Models

Welcome to the Mental Models section of When Notes Fly, our editorial library focused on practical knowledge, frameworks, and explainers in Concepts. We cover the topic from multiple angles, from foundational concepts and historical context to modern applications, common pitfalls, and step-by-step guides. Every article is researched and written by hand, with care taken to cite reputable sources and to keep the tone honest about what we know and what is still debated.

Below you will find 4 articles in this section. Use this list to browse the latest pieces, follow a thread of related ideas, or pick a single article to read in depth. If you are new to Mental Models, start with the foundational explainers near the top; if you are already familiar with the basics, scroll for the deeper case studies and applied frameworks.

Articles in Mental Models

• Ockham's Razor vs Hanlon's Razor vs Chesterton's Fence — Expert-written explanation of three classic reasoning heuristics with when to apply each, common misapplications, and decision examples.
• First Principles Thinking vs Systems Thinking — Expert-written comparison of first principles thinking and systems thinking with decision criteria for when each produces better results.
• First Principles Thinking — First principles thinking explained from Aristotle to Elon Musk. The five-step method, real examples from SpaceX battery costs to pharmaceutical pricing, and when the framework fails in expert domains.
• Cognitive Biases Everyone Falls For — Fifteen cognitive biases that distort reasoning, each paired with a peer-reviewed example and a practical countermeasure you can apply immediately.