This book brings together Peter Culicover's most important observations on the nature of syntax and its place within the architecture of language. Over four decades he has sought to understand the mental system in which linguistic expressions are processed. This has led him to re-formulate the balance between the requirements of interpretation and the role of syntactic structure; to examine the nature of the empirical basis in which particular structural analyses can be applied to linguistic expressions; and to consider the extent to which such analyses reflect judgements based not only on linguistic competence but on computations developed in the course of acquiring or using a language. After a brief a retrospective the author opens the book with the Simpler Syntax Hypothesis, the pioneering article written with Ray Jackendoff that fundamentally rebalances the elements of 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.