At a wedding, someone says “I do.” Is that a report about a marriage?

No. Saying “I do” is itself the act of getting married. Before that word, there was no marriage; after it, there is. “I do” doesn’t describe a fact — it creates one.

That observation is where the philosopher J. L. Austin’s 1962 book How to Do Things with Words begins.

Some sentences can’t be measured as true or false

School teaches us that a sentence describes or reports something, and that such a sentence can be true or false. “It’s raining today” is true if it’s actually raining, false if it isn’t.

But what about these?

None of these is true or false. It would be odd to ask someone who just said “I do,” “Is that true or false?” Instead, these sentences share a different property: saying them just is doing something.

Austin calls this kind of sentence a “performative” — it performs an act rather than describing one. He gives the ordinary, truth-evaluable kind of sentence a companion name: “constative.”

Sometimes it doesn’t work

A performative can fail in a way quite unlike being false. Act out a wedding on a stage, and the actors don’t actually get married. Let someone with no claim on a ship christen it, and the name doesn’t stick. Tell someone “I promise” with no intention of keeping it, and the promise rings hollow.

Austin sorts these failures into two kinds:

  1. The act never comes off at all — if the person running the “ceremony” has no standing to do it, no marriage happens, full stop.
  2. The act comes off, but insincerely — the promise counts as a promise, but since there’s no intention behind it, it’s an empty one.

Getting married, naming a ship, placing a bet — each needs the right procedure, the right circumstances, and the right state of mind. A performative only succeeds when all of that lines up.

A phrase you can always insert

Austin notices another neat trick. “I promise” can be rephrased as “I hereby promise” without changing the meaning at all. So can “I do” — “I hereby do” (well, almost — but “I hereby vow” works).

Now try that trick on an ordinary sentence. “The cat is on the mat” rephrases just as smoothly into “I hereby state that the cat is on the mat.” The meaning doesn’t change here either.

Which raises a question: is “state” secretly a member of the same family as “promise” and “vow”? Is there a hidden act of stating lurking behind every plain old sentence we thought was just describing the world?

At this point, Austin realizes that the line he first drew — performative sentences on one side, ordinary (constative) sentences on the other — was only ever part of a bigger picture.

Three layers inside every act of saying

That bigger picture looks like this. A single utterance actually contains three layers at once:

  1. Saying something at all (uttering the words “if it rains tomorrow, I’ll stay home”)
  2. Doing something in saying it (thereby promising, warning, requesting, and so on)
  3. Bringing about something by saying it (reassuring, startling, persuading the listener)

Both “I do” and “the cat is on the mat” carry all three layers. It’s just that we usually notice layer 2 in one case, and get distracted by layer 1 (what’s literally being said) in the other.

What the book did

Put together, the book’s argument runs like this:

Judging sentences only by true-or-false misses some of them entirely. → Gather up those sentences (performatives) and a different standard appears: does the act come off, or not? → Dig further, and the same machinery turns out to be hiding inside ordinary true-or-false sentences too. → So what’s really needed is a bigger picture that covers every utterance at once.

“To utter words is, more often than not, already to do something” — that’s where this slim book ends up.

To see each of its discoveries taken one at a time, read How to Do Things with Words: Six Ideas, One at a Time.