I asked David S. at work for a suggestion and this came up first. Here's his summary:
A French anarchist studies the complex language of an endangered Amazonian tribe while aliens make a strange deal with the United States government. Short (~200 pp) and very interesting.
The Chicago Public Library's copy is authentically 1973. The title refers to centre embedding, a syntantic/grammatical concept that is explained briefly towards the beginning; it was and remains unclear to me why it would contain the secrets to the universe. I was expecting something more semantic, like homomorphic encryption, or Douglas Adams's idea that understanding life, the universe and everything demanded the construction of the Earth, or Kurt Gödel's cute syntactic tricks. The violent response to the coldly transactional aliens was somewhat predictable given the time it was written. I chugged it over a few days and enjoyed it for what it was. There's the odd gross out (a witch doctor munching on a living child's brains, for instance) and I guess I have never felt comfortable with English notions of mental healthcare since I read Will Self's Quantity Theory of Insanity. The ending fails to evoke the emotional state that the aliens purportedly sustained for 12,000 years.
Anoop Sarkar explains the linguistics some more, and is right to observe that Watson's cynicism is wearing.
David S.'s second suggestion was Gene Wolfe's The Fifth Head of Cerberus, which I also got from the Chicago Public Library but didn't get far into: the prose is a bit impenetrable. That first novella may have been a little heavy on the centre embedding.