My thesis develops along several themes. I begin by looking at the relationship between literature and philosophy. I then study Stanislaw Ignacy Witkiewicz's novels Farewell to Autumn and Insatiability, and his metaphysical categories from the perspective ofthe philosophical writing of Soren Kierkegaard. The first theme explores the question of the fusion of literature and philosophy and establishes a theoretical background for the analysis of novels through a philosophical perspective. It also provides an explanation for my choice of the hermeneutic methodology for the analysis I undertake in my thesis. The main aim of my thesis is the analysis of Witkiewicz's novels through the application of Kierkegaardian concepts. Referring to Kierkegaard's philosophy places my analysis in the domain of existentialism. I explore his concept of irony, as introduced in The Concept of Irony, and treat it not merely as a rhetorical figure but as a particular existential stance which accepts that human existence extends beyond the `here and now'. I provide an elaboration ofthe philosophical nature of Kierkegaardian irony when I explore his understanding of existence as being a process of continuous becoming in the quest for knowledge, as portrayed in The Concept of Anxiety. Subsequently, I employ Kierkegaardian philosophical irony in the analysis of Witkiewicz's work. Initially, I refer Kierkegaard's concepts to Witkiewicz's metaphysical categories and by so doing emphasize their existential character. I then employ them in the analysis of Witkiewicz's novels as I treat his narratives as a realisation of existential themes. I study the way the existential nature of Farewell to Autumn and Insatiability is manifested. The model of Kierkegaardian irony enables me to treat Witkiewicz's playfulness as a particular expression of an ironical stance. I study the variety of forms his playfulness takes. I look at the way it has been expressed in the development of his fictional world and through the language and style of the narrative, which together create the overall impression that Witkiewicz's narratives constitute a particular playful communication between the author and reader. I also indicate that this playfulness accompanies, or is an expression of, deep concern for the most fundamental questions about human existence. I indicate the direct and indirect presence of existential reflections in the text. As a result I demonstrate that Witkiewicz's novels constitute a playful, ironical expression of profoundly existential reflections about human existence, and in this way, encompass his own quest for meaning.