This book is a defense of the classical beneficiary theory of rights. Its heart forms the idea that rights assure goods to their bearers by implying duties for others. This theory has come under attack from two sides. Firstly, its traditional rival, the "will" theory of rights conceives of the exercise of a right as a manifestation of the right-holders autonomy. However, recently a new challenge arose through the "new" beneficiary theory of rights developed by Neil MacCormick and Joseph Raz. This book is an attempt to show that, correctly understood, the classical beneficiary theory is preferable to both.