What happens to language when a Name cannot be replaced? Christus Solus is not a book about belief. It is a study of how one Name alters the grammar of every sentence that dares to contain it. From Koine Greek to ecclesiastical Latin, from creeds to confessions, from verbs to articles, the Name Christus does not behave like any other noun. It does not describe. It reorganizes. In this groundbreaking linguistic inquiry, Agustin V. Startari traces a formal pattern: wherever Christus appears, substitution fails, equivalence collapses, and the sentence loses neutrality. Grammar tightens. Predicates align. Scope narrows. This is not theological rhetoric. It is structural analysis. Drawing on ancient texts, syntactic markers, and the refusal of plural or apposition, Christus Solus exposes the Name not as a symbol, but as a grammatical operator. The result is a sentence that declares, not negotiates. This book is written for readers who want clarity without reduction, doctrine without simplification, and language without metaphor. It challenges linguistic conventions, bypasses dogmatic filters, and opens a new path: reading Scripture as a structure shaped by one irreversible word. One Name. No replacement. No equivalence. Only grammar, altered. About the author Agustin V. Startari is a linguist, author, and researcher in historical studies. His work explores the intersection of syntax, epistemic authority, and artificial language structures. He is the author of Executable Power, The Grammar of Objectivity, and Grammars of Power, and holds affiliations with the University of the Republic (Uruguay) and the University of Palermo (Argentina). Website: www.agustinvstartari.com ORCID: 0009-0001-4714-6539 Researcher ID: K-5792-2016