This paper aims to contribute to the panel interested in resolving the question of how humans exist with their signs in the reality that surrounds them during the course of their daily lives. This reality is labeled in some conceptual and methodological frameworks as Umwelt, Dasein, Lebenswelt, or le monde vécu, in some others as cosmovision or worldview, and, otherwise, semiosphere, biosphere, and noosphere, being placed within the broader scope of the so-called geosphere studies. Correspondingly, the investigative object of the following research report will encompass the concept of Dasein used in German philosophy to describe the environmental properties related to how humans live in the world, of which they are aware, about which they communicate, and which they observe as given to them. These properties are endowed with meaning expressed in synonymous terms of essence, existence, experience, transcendence, and even donation. Regarding the investigative perspective of epistemology as a semiotic cartography of knowledge, the ontology of things and their gnoseological approachability in the world will be exposed by the author of this paper according to the subjective or objective position of a knowledge-seeking subject in his or her orientation towards other beings in the environment. In the light of existentialist semiotics, the cognitive epistemic research will focus on the modality acts of the personal-social self, which transcends to another reality to become an individual as someone who wishes to appear in the mental eyes of other individuals or who aims to see himself in the mirror of the world.