Soliloquia is the first oratorio of Klaus Huber which is a work of very large proportions. In the first chapter, we propose a detailed analysis. The second chapter develops the idea of monumental testimony. It starts from Tzvetan Todorov's three humanistic pillars (the autonomy of the subject, the finality of the other, the universality of all) to collate two other works of Klaus Huber of the same kind (...inwendig voller Figur..., Erniedrigt-...) which show his engagement in the direction of shaking the consciousness of the listeners to open it to the world. His writings will contribute to inform us about his positions. A sketch of a genealogy opens some interpretative « humanistic » perspectives of some works in the western history of music from some works since the 15th century. Finally, as an epilogue, the presentation text of Klaus Huber for Miserere Hominibus (creation 2006) shows his last preoccupations in all subjects and opens a field of thoughts to the future.