This book is aimed at investigating the consequences of epistemological positions for the foundation of linguistic semiotics with special reference to the concepts of sign and meaning. In the succeeding five chapters, the reader is provided with a panorama of theory-and-method related views that show how far the specification of the subject matter of semiotics is dependent upon the ontological and gnoseological commitments of scientists. Language as a system of shared means of signification and communication is discussed here with respect to its systemic and ecological properties constituting an investigative object of linguistics proper or an aspect of other objects studied by adjacent disciplines. Separate attention is devoted to the concept of subjective significance uniting the domain of human semiotics within the framework of natural and cultural sciences.