How could Noam Chomsky say that Esperanto is not a language?

‘Cause he’s a reductionist shmuck.

Longer answer:

What Jens Stengaard Larsen’s answer said. To the Noam (tar his bones!), linguistics is an arm of neuropsychology, and anything that doesn’t reflect the (big sarcastic scare quotes) natural development of language is not of scientific interest.

Lots of evil narrowminded blinkered linguists share the naturalist bias against Esperanto and other conlangs (How do professional linguists react to Esperanto?). Many scholars though don’t share Chomsky’s particular take on language, including:

• Actual neuropsychologists
• Almost all historical linguists
• Pragmaticists
• Most Typologists
• Sociolinguists
• Anthropological linguists
• Fieldworkers
• Corpus linguists
• Linguists on the West Coast of the States and in Australia

Edit: Oh and I forgot to add (especially for Vadim Berman):

• computational linguists!

Especially after Chomsky took the NATO funding for machine translation in the 1960, and ran…