The main focus of this thesis is explaining the notion of epiphany in James Joyce's novel A Portrait of the Artist as a Young Man, how the epiphanies in the novel affect the development of the protagonist, Stephen Dedalus, their relation to Joyce's theory of aesthetics, as well as the development and shift in the narrative aspect of the novel. In the first part of the thesis, I will introduce the character of Stephen Dedalus, the protagonist of the novel, contextualizing his line of thought, the first steps of his development as an artist and philosopher and his uniqueness as an individual. I will present the importance of epiphanies to Joyce's characters and Joyce himself, as well as putting the notion of epiphany in the context of modernist literature. Joyce's aesthetic theory will also be touched upon, as epiphanies are an important element of it. Epiphanies will be examined as a general term and concept, as well as their different roles in the fields of aesthetics, literature and philosophy. Next, I will examine different specific epiphanies in the novel, explaining the context of their happening, as well as their effects on Stephen's character and the narrative aspect of the novel. In the final part of the thesis I will round up all the points that were discussed, presenting a final, cohesive explanation of the epiphanies in the novel.