The world is in a terrible mess. It is toxic, irradiated, and full of injustice. Aiming to stand aside from the mess can produce a seemingly satisfying self-righteousness in the scant moments we achieve it, but since it is ultimately impossible, individual purity will always disappoint. Might it be better to understand complexity, and, indeed, our own complicity in much of what we think of as bad, as fundamental to our lives? 'Against Purity' argues that the only answer - if we are to have any hope of tackling the past, present and future of colonialism, disease, pollution, and climate change - is a resounding yes.