How many personal principles should you have?

Five to eight. Start with three. The number is not arbitrary and it is not about memory tricks — it falls out of three structural constraints that any working set of principles has to satisfy at once.

Constraint 1: it must be recallable without looking

A principle only works if it arrives at the moment of decision. Nobody opens a document mid-conversation when someone is asking for a commitment. So the operative set is whatever you can list from memory while under mild pressure — and for most people that is somewhere between five and eight items, not fifteen.

This gives you a simple diagnostic. Right now, without looking, list your principles. Whatever you produced is your real list. The rest of the document is aspiration, and aspiration does not participate in decisions.

Constraint 2: conflicts must stay visible

The interesting work happens where two principles collide: candour versus kindness, ambition versus presence, speed versus care. With six principles there are fifteen possible pairings, and you can hold the important ones in view and write explicit tiebreakers for them. With twenty principles there are a hundred and ninety, and you will never map them.

Unmapped conflicts do not disappear — they get resolved silently in the moment, by whichever principle happens to be more convenient. A large list feels more complete while actually giving you less control, because it hides the trade-offs it contains.

Constraint 3: the review has to fit in ten minutes

A weekly review that runs long stops happening. Ten minutes divided across a list means roughly a minute each, which is enough to notice a problem and not enough for twelve items. The review cadence effectively caps the list size, and since the review is what keeps the whole system honest, the cap is not negotiable.

Why people end up with too many

• Confusing standards with principles. "I read before bed" is a behaviour standard, not a principle. It belongs underneath one. Most twenty-item lists are really five principles with their implementations mixed in — the fix is to nest them, not to cut content.
• Collecting other people's. A good line from a book is easy to add and costs nothing at the moment of adding. It costs later, as review time and as diluted attention.
• Refusing to retire anything. Principles feel like commitments, so deleting one feels like a character flaw. It is not. A principle written to fix a problem you no longer have has done its job and should be retired with thanks.
• Covering every life area. There is no rule that you need one for health, one for money, one for relationships. Write for where you actually have friction. Some areas of your life do not currently need governing.

How to cut a long list down

1. Nest. Go through and ask of each item: is this a decision rule, or is it what living a decision rule looks like? Move all the second kind underneath the first kind. Most lists shrink by half here without losing anything.
2. Test for teeth. For each remaining principle, name a specific occasion in the last six months when it cost you something. No occasion, no evidence it is operating. Move those to a "maybe" file rather than deleting, so cutting feels cheap.
3. Merge the overlaps. Two principles that have never disagreed with each other are probably one principle written twice.
4. Rank the survivors and take the top six. Ranking forces the tiebreaker conversation you have been avoiding, which is worth doing even if you keep them all.

If you are starting from zero

Write three. Live them for a month. Add a fourth only when a real situation arrives that none of the three addresses — that is the only good reason to add one, and it guarantees the addition is earned rather than imagined.

Three principles you consult weekly will change more of your behaviour in a year than twenty you admire. The list is not a portrait of your values; it is a tool you pick up under pressure, and tools get smaller as they get better.