This book brings together many of Peter Culicover's most significant observations on the nature of syntax and its place within the architecture of human language. Over four decades he has sought to understand the cognitive foundations of linguistic theory and the place of syntactic theory in explaining how language works. This has led him to specific proposals regarding the proper scope of syntactic theory and to a re-examination of the empirical basis of syntactic analyses, which reflect judgements reflecting not only linguistic competence but the complexity of the computations involved in acquiring and using language. After a brief a retrospective the author opens the book with the Simpler Syntax Hypothesis, an article written with Ray Jackendoff, that proposes significant restrictions on the scope of the syntactic component of the grammar. The work is then divided into parts concerned broadly with representations, structures, and computation. The chapters are provided with contextual headnotes and footnote references to subsequent work, but are otherwise printed essentially as they first appeared. Peter Culicover's lively and original perspectives on syntax and grammar will appeal to all theoretical linguists and their advanced students.