First Principles

First Principles / 第一性原理

> "It's how it's usually done" is not a reason. Re-derive it, or don't claim it. > "通常这么做"不是理由。要么重新推导,要么别用它当依据。

The discipline / 纪律

Reason from first principles — not "how it's usually done", but "why it must be done this way": 从第一性原理出发——不靠"通常怎么做",靠"为什么必须这样做":

1. Define the problem down to its most basic form. / 把问题定义到最基本形态。
2. Find the facts that can't be reduced further. / 找到不可再简化的事实。
3. List your assumptions explicitly — and challenge them. / 显式列出并挑战所有假设。
4. Strip away convention, best practice, industry defaults. / 剥掉惯例、最佳实践、行业默认值。
5. Rebuild the solution from constraints and goals alone. / 仅从约束和目标重新构建方案。

Forbidden: "this is the usual approach" as a justification. Reasoning over recall. 禁止: 拿"这是通常做法"当理由。推理优先于回忆。

When this triggers / 触发时机

• About to make an architecture / data-model / service-split / protocol choice.
• About to cite "usually / best practice / everyone does it this way" as a reason.
• About to copy a common template without saying why it fits this case.
• A design feels "weird" but you're unsure why it doesn't follow the common pattern.

Done criterion (verifiable) / 完成判据（可验证）

✅ The approach lists three things: (a) the default/convention you're stripping away, (b) the specific constraint or fact that overturns it, and (c) how the conclusion would change if that constraint changed. Missing any one = not done. ⚠️ You leaned on convention because the constraints were unclear — name what you'd need to know to decide properly. ❌ The only reason given is "it's standard". Re-derive from constraints before committing.

Worked examples / 实战反例

Real before/after cases for this discipline live in [EXAMPLES.md](./EXAMPLES.md) — read them before you act. 本纪律的真实 before/after 反例见 [EXAMPLES.md](./EXAMPLES.md) —— 动手前先对照。

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: yli769227-jpg
• Source: yli769227-jpg/agent-discipline
• License: MIT

Install and usage instructions live in the source repository linked above.