a public library · fifteen subjects
Short serious lessons for the inquisitive person.
Written for readers who want the real mechanism rather than the cartoon version. Each lesson includes a passage, a vocabulary glossary, and a five-question quiz with explanations for every wrong answer.
✥ ✥ ✥
The fifteen subjects
Biology
How living systems work at the cellular and organismal level, written for readers who want the real mechanism rather than the cartoon version.
9 lessons
Chemistry
How matter is structured and transformed at the molecular scale, with attention to the reasoning behind chemical concepts rather than memorization.
7 lessons
Engineering
How designers work under constraints — strength, cost, failure, time — and the reasoning that turns a physical principle into something that holds up in the world.
7 lessons
Earth Science
How the planet works as a coupled system: rocks, oceans, atmosphere, and the deep-time processes that shape the surface we live on.
7 lessons
Philosophy
Arguments about identity, mind, knowledge, and value, treated with the same care a careful philosopher would extend to a colleague's strongest objection.
7 lessons
Physics
How physical systems are modeled, where the models break, and how physicists choose between competing accounts of the same phenomenon.
7 lessons
Investing
How markets, portfolios, and risk actually behave. Educational rather than advisory: the lessons describe what is, not what to do.
7 lessons
Business
How firms are organized and how they compete — strategy, operations, and the structural reasons some businesses persist while others don't.
7 lessons
Literature
Close reading of poems, novels, and plays, with attention to how the work makes meaning rather than to summary alone.
7 lessons
Critical Thinking
How to evaluate arguments, weigh evidence, and notice the moves that good and bad reasoning have in common across very different topics.
7 lessons
Mythology
How human cultures have used myth to think about origins, death, fate, and the social order — read seriously, neither as literal history nor as quaint superstition.
7 lessons
War History
How wars actually unfolded — the contingencies, contested causes, and human decisions that shape outcomes — with care to avoid neat narratives that flatten what really happened.
7 lessons
Astronomy
How astronomers learn about the universe — what we measure, how we measure it, and what counts as evidence at scales no instrument can directly probe.
7 lessons
Psychology
How the mind actually works — memory, learning, perception, social behavior — written with attention to what the experiments showed and what later research complicated.
7 lessons
Religion
Introductions to the major living religious traditions and close readings of their foundational texts — engaged seriously as intellectual and historical systems, not as positions to defend or dismiss.
10 lessons
Featured lessons
Investing · Investment Strategy
Active and Passive Management: The Long-Running Debate
In 2007, Warren Buffett offered a wager: over the next ten years, a plain S&P 500 index fund would beat any basket of hedge funds a professional could assemble, after fees.
4 min · comparison
Engineering · Systems Design
Centralized and Distributed Systems: Two Ways to Build at Scale
Imagine a busy library with a single front desk. Every borrower checks books in and out at one counter, where one librarian holds the only ledger. The system is easy to understand: there is exactly on…
4 min · comparison
Physics · Physics Foundations
Classical and Quantum: When Each Description Breaks Down
A baseball arcing toward the outfield and an electron drifting through a copper wire are both, in some ultimate sense, governed by the same physics.
4 min · comparison
Each lesson passes a five-dimension review — clarity, accuracy, pedagogical depth, distractor quality, and adherence to subject-specific guardrails — before it appears here. Borderline lessons are queued for human review rather than published.