Vladimir Sergeevich Solovyov was one of the most influential Russian religious thinkers and philosophers of his time. His literary heritage is among the largest and weightiest in the Russian language, enjoying continued relevance particularly in matters of East-West ecumenism. From 1883 to 1889, Solovyov focused especially on questions of the universality of the Church. In One and Holy, many of these essential ecclesiological writings have been gathered together for the first time in English translation. The collection opens with The Great Controversy, the first of Solovyov's major ecclesiological works and one that marks the beginning of his interest in the Roman Church. Arguing that the Church cannot be understood except as a universal reality, he concludes that her inner life goes beyond any particular local expression, thus offering a basis for reunion between East and West. This text is followed by several shorter works, including ""Some Explanations Regarding the Great Controversy"" and ""The Response to N. Ia. Danilevskii,"" in which Solovyov defends his ideas against Russian critics. His next major work, The History and Future of Theocracy, articulates a framework for unified Christian society, treating issues of doctrinal development and dogmatic differences between East and West. The collection includes his ""Letter to Strossmayer"" and concludes with The Russian Idea, addressed to prominent Catholics of his day.