This article explores the fundamental philosophical theme of Being, identified by Karl Jaspers as the central motive of all philosophizing. Starting with Jaspers' claim that philosophy has always addressed "Sein," the text examines the semantic and ontological implications of this concept in Latin, Greek, and Czech. The author highlights the inherent ambiguity of the word "is"—a problem noted by Aristotle—and stresses the need to distinguish between its formal, auxiliary usage and a deep investigation into its nature. The article critically evaluates the traditional distinction between essence and existence, finding it insufficient for understanding "Being." Instead, it questions what is truly meant when we focus on the nature of that which "is." Ultimately, the text argues that philosophy is not merely concerned with objectively given entities or "real" things, but seeks a deeper comprehension of the act of Being that transcends simple factual occurrence.