Based on Arnold Gehlen’s work, the XXth Century philosopher founder of Anthropobiology, a field that integrates Biology – especially Ethology and Anatomy–, Cultural Anthropology, Pragmatics and Philosophy, I trace back this important theoretical trend with the aim of answering the following questions: How does Gehlen’s work define the concepts of body and language? How these concepts clarify a non-metaphysical approach of the definition of human being? How does the author explain the nexus between outside and inside, inner and outer, body and soul, summarizing, between the inner life and the world?