In the present thesis the author professes to offer neither a systematic account of Sophoclean theology (if indeed there is such a thing) nor a study of the epistemological problem per se in Sophoclean tragedy. His purpose is rather to illuminate - partly expanding on a brief but suggestive study by Hans Diller ("Gottliches und menschliches Wissen bei Sophocles", Kiel 1950) - the ways in which the epistemological chasm between Man and God in Sophoclean tragedy becomes manifest through a 'collision' between the incompleteness and limitedness of human knowledge on the one hand and the transcendence and the unknowability of the gods on the other. An introductory chapter is prefixed which deals with the development of the idea of divine unknowability in archaic Greek literature and in Presocratic philosophy. There follows a detailed examination of the extant plays one by one (with special emphasis on the close reading of practically all the choral odes), by means of which the author endeavours to demonstrate that the centrality of the epistemological problem (in relation, always, to the inscrutability of the Godhead) in Sophocles, far from reducing his dramas to abstract philosophical treatises, contains a tremendous tragic potential and makes for powerful plays. Aspects of each play's structure, of its thematic articulation and of its vocabulary are studied, while a variety of methodological approaches are employed in order to illuminate problems of interpretation. All important secondary literature is cited and / or discussed. Thus, while never losing sight of its central concern (divine unknowability, limitedness of human knowledge), the present thesis also aims to be a thorough study of Sophoclean tragedy as a whole.