A particular set of theories say that the State came into existence as a result of an actual or hypothetical agreement, between the ruled and their rulers, defining the rights and duties of each. Although similar ideas can be traced to the Greek Sophists, these theories had their greatest currency in the 17th and 18th centuries and are associated with philosophers such as the Englishmen Thomas Hobbes and John Locke and the Frenchman Jean-Jacques Rousseau. Which of the following theories are we talking about here?