Recent developments in literary modernism have turned towards the archive to study the process of how literary narratives develop over time. This book focuses on genetic criticism, or manuscript-based studies, to show how authors D.H. Lawrence, Anaïs Nin, and James Joyce engaged with theories of the mind during their process of literary composition. Instead of applying the frameworks of psychoanalytic theory to final published texts, this book examines archival and peritextual materials prior to publication, and in doing so offers new ways to study modernism's engagement with theories of mind. This book examines D.H. Lawrence's vitriolic psychoanalytic essays, looks at how Anaïs Nin's fastidious editorial practice as a diarist was facilitated by her therapy with Otto Rank, and analyses how the complex relationship between James Joyce and his allegedly schizophrenic daughter Lucia impacted the composition of Finnegans Wake over time. In effect, this book develops the methodology of genetic criticism by studying the historical and dynamic relationship between mind and text during the early 20th century.