Everett's most controversial claim is that the Pirah language lacks 'recursion' - the ability to build an infinite number of sentences within sentences, regarded by Chomsky-ists as perhaps the most fundamental characteristic of human language. The Grammar Of Happiness interweaves the tale of Everett's attempt to return to the Pirah with the story of his personal journey since the sixties - from drug-taking musician to evangelical missionary to rabble-rousing academic. It's the adventurous tale of losing faith but finding happiness.