This seminal collection, 'The Freud-Jung Correspondence,' meticulously edited by William McGuire, offers an unparalleled window into the formative years of psychoanalysis. It chronicles the intellectual relationship between Sigmund Freud and Carl Gustav Jung, two of the most influential figures in modern thought. Spanning from 1906 to 1914, these letters reveal the development of their groundbreaking theories, their initial close collaboration, and the eventual ideological schism that profoundly reshaped the landscape of depth psychology. Readers gain intimate insights into their personal and professional struggles, theoretical agreements, and the fundamental differences that led to their famous split, making this a crucial document for understanding the history of psychoanalysis.