Paul Grice, 1975: there’s a massive gap between literal words and what we actually communicate. The bridge is the Cooperative Principle — the shared assumption that conversation partners are cooperating, trying to be relevant and sensible.

“I’m out of petrol.” → “There’s a garage down the road.” Literally: two unrelated facts. Via Cooperative Principle: the garage has fuel, you can get there, this solves your problem. None of that is stated. All of it is implied and correctly received.

The Four Maxims:

  1. Quantity — say enough, not too much or too little
  2. Quality — tell the truth
  3. Relation — be relevant
  4. Manner — be clear

We run these constantly and automatically. When something violates the maxims, the brain flags it immediately — the NPC test: “Have a good day.” vs. “Enjoy the next 24 hours.” Same information. The second feels threatening because it’s weirdly precise about a quantity, which signals something.

Why this matters:

  • Most of what we communicate isn’t in the words
  • Most misunderstandings come from different assumptions about what’s being implied
  • Manipulation often operates through implicature, not lying

Marketing example: “Low in fat” — technically true. Implies competitors aren’t. Cooperative Principle exploited. Not a lie; not quite fair.

See 2026-04-11-flouting-a-maxim-implies-without-lying for the distinction between violating and flouting.