The Institutes are a complete exposition of the elements of Roman law and are divided into four books—the first treating of persons and the differences of the status they may occupy in the eye of the law; the second-of things, and the modes in which rights over them may be acquired, including the law relating to wills; the third of intestate succession and of obligations; the fourth of actions and their forms. For many centuries they had been the familiar textbook of all students of Roman law.