The subject of syntactic symmetry in generative grammar has been largely overlooked, and this work sets out to demonstrate that the internal structure of nouns and clauses is essentially parallel. Global evidence from the world''s languages are provided throughout. Dr. Brown completed her Ph.D. in English Language and Linguistics at the University of Durham in 1996. Whilst she was a postgraduate student, the department earned a 5* research rating (highest grade) under the direction of Professor Joseph E. Emonds, a world-class syntactician known for his writings on ‘structure preservation'', ''alternative realisation'', ‘well-formed lexical entry'', and the syntax of local processes. Professor Emonds''s intellectually innovative lectures at Durham, together with his 1985 book *A Unified Theory of Syntactic Categories*, were fertile sources of inspiration for the present work. *A Unified Theory* characterised fundamental asymmetries across the four lexical categories of N, V, A, P, and was original and prescient in its content. This study, derivatively, is the first of its kind to expressly call for syntactic symmetry in generative hierarchical structure.