John Barton used to live in the non-disabled world. Then he developed symptoms of an obscure inherited condition that affected his mobility, closely followed by Parkinson's disease. And suddenly he found himself propelled into the kingdom of the disabled. There are two worlds, he writes: 'In one lies power, privilege and validity, in the other, the supposed lack, shame and misery of the invalids. The barriers that separate them - physical, political and psychological - diminish us all. They cripple our societies.' This is a book not about disability but about our shared humanity. Barton takes us on a journey through history, politics, sociology, medical science and psychology, to explore the meanings of disability. Why do we, as a species, find it so hard to share our common world with people who are different from us? When you meet a disabled person in the street, socially, or in your work, do you pass the Humanity Test? Read this book. You may learn something.