The texts gathered here, unpublished in French, were originally published in the early 1980s. Different in size or tone of the subject; they are based in particular on a rigorous and original examination of the famous text of Thomas More Utopia (1516) and books of H.G. Wells published between 1895-1901. By bringing them together for the first time as a coherent whole, this book shows the importance of this theme of utopia for the sociologist. This volume has several interests. It allows researchers - historians, literary, sociologist, anthropologist or political scientists - to discover unexpected analyzes of these canonical texts, and a renewed definition of what appears not as the only literary genre of "utopia", but rather a social practice and a form of knowledge. It also offers the opportunity to make contact with a "second Elias", richer and more complex than what is often presented. The latter also addresses topics that are less or less known to him, such as the question of the possible futures of the past and the future, the relationship between "hard" sciences and social sciences, the problem of politics. in the global era and the exercise of critical thinking, worked between expressed concerns and a rigorous requirement of distancing. In his own unique way, Elias takes up questions that are still highly relevant today - such as that of utopia. Clear thinking, very structured and out of step with the way in which many contemporary debates arise. We can also be carried away by this singular voice that deploys a vast thought, imposes a disproportionate ambition on the social sciences, reevaluates the role of the imagination, suggests new categories of political thought and develops an original sociological vision of the world. Such is at bottom the rational utopia of Elias that this book delivers.