Blending the latest academic research with case studies of famous figures, this highly insightful book presents 'doubt' as a central concept for psychology. It is a concept which has been oddly neglected in the past, despite its ubiquitous nature and far-reaching influence. Exploring everything from self-doubt and impostor syndrome to the weaponisation of doubt with respect to climate change and the marketing of cigarettes, bestselling author Geoffrey Beattie navigates readers through the various ways doubt can start and develop, changing the individual in the process. Written in Beattie's distinctive and engaging style, Doubt takes the reader into the lives of transformational thinkers, artists, scientists and writers to explore how and why doubt was crucial in their lives and how the likes of Kafka, Jung, Picasso and Turing succumbed to doubt or learned to control it. Beattie argues that doubt is central to the self; it can be either a safeguarding mechanism or a distraction, rational or irrational, systematic or random, healthy or pathological, productive or non-productive. The book helps readers to recognise how doubt may have been operating in their own lives and to identify how and when it has been used against us - for example, to prevent climate action - and at what personal and societal cost. Presenting a compelling case for why doubt cannot be ignored, this book is of major interest to academics from a wide range of disciplines, including social and cognitive psychology, clinical and counselling psychology, sport psychology, sociology, business studies, politics, art and literature, as well as the general public, who may well see something of themselves in its pages.