At the beginning of the twentieth century, Ireland was at a stage of crisis in the search for a definitive, national Irish identity. Such a search was in vain and Sean 0' Casey's works show why. He voiced the end result in the cycle of cultural and political nationalism. This was the brutal reality and exposition of those who had suffered and endured the mystical visions of others. The topics that will be explored in relation to 0' Casey, concerns his distinctions between the private life and the public life of the Irish working classes, and how these act as a microcosm for more general areas in Irish life. His observations of the several religions becoming widespread in Ireland, and the diverse views towards the equally diverse political factions, led him to question the whole idea of an Irish identity. In a time of modernist thought, 0' Casey highlighted the conflict between official ideologies and individual experiences. He was aware that the modern individual was developing a free mind. He tried to explain people to themselves in an attempt to help them understand their experiences: the hope and despair that they endured during troubled times in their country. 0' Casey is the great hero of Irish theatre. He rejuvenated the Abbey's prestige at a time of crisis, and for that he was forced into exile due to continuous rejection. He tried to expose the fascism, the aggressively nationalist and centrally autocratic tendencies, of the Irish national cause that had somehow seeped into the aesthetic and cultural domain. This Final Year Project will attempt to show how 0' Casey was not frightened to address these brutal truths, and how continuous critical assessments of his works can be adapted to a multitude of different social situations through the flux of time. It will determine the didacticism that he wished to express and one that still exists through his medium today.