Does recognition of the basic human right to subsistence imply that the needy are morally permitted to take and use other people’s property to get out of their plight? Should we respect the exercise of this right of necessity in a variety of scenarios – from street pickpocketing and petty theft to illegal squatting and encamping? In this concise and accessible book, Alejandra Mancilla addresses these complex and controversial moral questions. The book presents a historical account of the concept of the right of necessity—from the medieval writings of Christian canonists and theologians to seventeenth century natural law theory. The author then goes on to ground this right in a minimal conception of basic human rights, and proposes some necessary and jointly sufficient conditions for its exercise. She confronts the main objections that may be posed against this principle and ultimately concludes that the exercise of this right should be considered as a trigger to secure a minimum threshold of welfare provisions for everyone, everywhere.