This book evaluates Noam Chomsky's contributions to linguistics and focuses on the historical justification for Cartesian Linguistics, the evolution of Chomsky's theorizing, empirical language acquisition work, and computational modeling of language learning. Chomsky claims that his view is situated within a rationalist Cartesian tradition and that only rationalists can account for all aspects of language. The work challenges both claims. Chomsky projects his own convictions onto Cartesians and his recent work has not lived up to early promises. The Minimalist Program has failed to produce scientific results, and empirical work in developmental psychology and computational modeling further challenge Chomsky's rationalist dogma.