This book explores how Kleinian psychoanalysis has developed over the past 75 years and how it illuminates human experience and relationships inside and outside the consulting room. The text will help the reader gain a deeper understanding of processes of splitting, projection, and identification in clinical work; a broader conception of how internal and external worlds interact and affect each other; greater clarity on key theoretical and ethical issues; and an overview of what the Kleinian tradition has contributed to mental health and wellbeing. Concepts are presented in a structured progression, accompanied by summaries of key papers by prominent clinicians. Offering an accessible account of a key strand of British Object Relations, this essential resource will be of value to trainee, newly qualified, and experienced psychodynamic counsellors and psychoanalytic psychotherapists, as well as teachers, social workers, and nurses.