This book provides a concise and highly readable reassessment of Iris Murdoch's engagement with philosophy throughout her life and proposes that she was, most importantly, a philosophical novelist. By investigating her use of philosophical argument in her fictional writing, it becomes clear that her narratives always depend upon a strong metaphysical underpinning. Leeson proceeds thematically through the philosophical phases of Murdoch's life and develops a clear argument that Murdoch reacts against the philosophies of Sartre, Plato, Nietzsche and Heidegger not only in her philosophical writings but also in her fiction. Indeed, it is in her fiction that her philosophical argument is most persuasive and accessible. This timely study provides new information regarding Murdoch's engagement with Martin Heidegger and also provides a detailed critique of critics who have overlooked Murdoch's engagement with philosophy within her fiction.