Activation Energy: Favourable Is Not the Same as Likely

Paper on a table will not burn, though burning releases energy. Something has to supply the initial push — and most stalled intentions are barriers, not disagreements about value.

Just-In-Time: The Buffer Was Hiding Something

Cutting inventory frees a lot of cash. The original reason for cutting it was different — stock conceals late suppliers and broken machines, and removing it forces them into view.

Modularity and Integration: Fit Against Flexibility

Control every part and tune the fit, or accept a standard interface and gain interchangeability. Which one wins turns on a single question — and the answer changes as a market matures.

Vertical Integration: Owning the Step That Decides the Product

Buying from specialists is usually cheaper, and sometimes it means you cannot be better than anyone else. The right boundary moves as an industry matures — and rarely gets revisited.

Fundamental Attribution Error: They Are Impatient, You Were Late

The same behaviour gets explained by character in others and by circumstance in yourself. The asymmetry is not mainly self-flattery — it is what you can and cannot see.

Organizational Design: Choosing What Will Be Easy to Build

An org chart looks like a diagram of authority. It works as a map of which conversations are cheap — and that is what ends up shaping the product.

Philosophy: The Questions Every Other Field Has to Assume

Physicists assume observation reveals reality; doctors assume suffering is bad. None of those assumptions can be tested by the field relying on them — and someone has to examine them.

Metcalfe's Law: Why Second Place Is So Much Worse Than Second

Ten times the users gives roughly a hundred times the possible connections. The exact formula overstates things — the underlying point about compounding leads does not.

Punctuated Equilibrium: The Puzzle Is the Stability, Not the Change

The fossil record shows long stretches where species barely change, then rapid shifts. The interesting question is not why change happens in bursts — it is what holds things still for so long.

Epidemiology: Everything Turns on One Number Crossing One

If each case produces more than one further case, an outbreak grows; below one, it fades. That threshold is simple — and almost everything else about the subject is context-dependent.

Amara's Law: Too Much in Two Years, Too Little in Twenty

The same technology gets overestimated early and underestimated late. Both errors come from drawing a straight line through something that is slow first and rapid afterwards.

Ecology and Climate: Feedbacks Decide the Outcome

Remove one predator and rivers can change course. The size of a change tells you little — what matters is whether the system amplifies it or absorbs it.

Creative Destruction: The Damage Is the Mechanism

New methods can only grow by taking resources from old ones. The productivity gain and the displacement are not cause and side effect — they are the same event seen from two sides.

Behavioral Economics: The Errors Point the Same Way

If people departed randomly from rational choice, the departures would cancel out. They lean consistently in the same directions — which is what makes them worth studying, and worth worrying about.

History: The Past and the Account of It Are Different Things

Every account is assembled from what survived, by someone who already knows the ending. That single fact makes events look more inevitable than they were — and explains why careful history sounds less certain.

Dunbar's Number: The Limit Is Attention, Not Memory

You can recognise thousands of faces and actively maintain far fewer relationships. The famous figure of 150 is contested — the underlying constraint is not.

Cognitive Dissonance: The Belief Moves Because the Action Cannot

When what you did clashes with what you think, one has to give. The action already happened and the belief is private — so people end up sincerely believing whatever justifies what they did.

The Medium Is the Message: The Form Does More Than the Content

Writing's real consequence was not that people could record things — it was that law could outlive its author. Every medium does work that no individual message controls.

Benford's Law: Why So Many Numbers Start With One

Around thirty per cent of numbers in real datasets begin with 1, and only five per cent with 9. People inventing figures don't reproduce that — which is how the pattern became an auditing tool.

The Central Limit Theorem: Why Bell Curves Are Everywhere

One die is flat. Ten dice added together make a bell curve. The shape is a property of adding independent things — which tells you exactly when to expect it and when not to.