 Book 4 opens with a discussion of the way in which the geographical location and features of the proposed city of Magnesia affect the ease or difficulty of creating a virtuous city. It then turns to consider the method of settlement of the proposed city, and the practical challenges of forming a group of settlers (whether they be from one or many states) into a genuinely new society. Here, the Athenian suggests that the easiest way to form new and good institutions in a society is for it to be blessed with a good tyrant who wishes to create institutions conducing to virtue. The Athenian moves on to ask what type of polity they ought to form; he answers by saying that the best ruler a city can have is god, and that they ought to imitate the rule of god by ordering their city in obedience to reason, the immortal element within themselves. These regulations set down by reason are to be called law (Laws  714A).[14]