Colorless green ideas sleep furiously

Where σ represents a
grammatical sentence.
See Phrase structure rules

Meaning

Furthermore, the two adjectives contradict ("green" is negated by "colorless"), and because word order is irrelevant within a NP or a VP, "colorless" is also negated by "green." This contradiction represents a violation of a fundamental law of cognitive reasoning, and a listener will by deduction understand that the next words in the sentence will likely be impossible to interpret. Finally, while "sleep" is a verb, in virtually all concievable cases "furiously" cannot be a property of "sleep."

The essential point is that, though words may follow a valid grammatical structure, they cannot form a meaningful sentence, or be a part of a meaningful phrase, if they violate their defined contexts. These contexts play an important role in the initial forming of logical sentences. As each word is simply a symbolic container for both greater and smaller contexts, the underlying structure by which these containers are organized, has important bearing on how they are composed to form sentences. Chomsky went on to explain that this underlying structure (of which the definition is a component) is more important than the grammar, when meaning is communicated: Sentences with the proper symbolic containers (words) may often be recomposed with more useful (for those listening) grammatical structure—but meaningless sentences, regardless if they have proper grammar, are hopelessly lost for meaning.

Other examples

There is at least one earlier example of such a sentence, and probably many more. The pioneering (yet mostly forgotten) French syntactician Lucien Tesnière came up with the French sentence le silence vertébral indispose la voile licite (`the vertebral silence indisposes the licit sail') to make essentially the same point in his 1954 book (which was mostly written in the late 1930s), the Estonian writer Eduard Vilde (1865-1933) wrote "Rabbits were running to the Eternity holding rainpipes in their mouths" etc.

There are doubtless earlier examples of such sentences, possibly from the philosophy of language literature, but not necessarily uncontroversial ones, given that the focus has been mostly on borderline cases. For example, followers of logical positivism held that "metaphysical" (i.e. not empirically verifiable) statements are simply meaningless; e.g. Rudolph Carnap wrote an article where he quite literally claimed that almost every sentence from Heidegger was grammatically correct, yet meaningless. Of course, non-logical positivists disagreed with this.

Examples like Tesnière's and Chomsky's are the least controversially nonsensical, and Chomsky's example remains by far the most famous.

John Hollander wrote a poem titled "Coiled Alizarine" in his book, The Night Mirror. It ends with Chomsky's sentence.

Referenced By