In the household, the man alone rules, thus he has no competition or adversary to contend with and does not need to exercise his reasoning as readily as in the city. Even if the individuals, the men, seem to live simply to complete their lives and achieve happiness, they can only do so by contributing to the city's perpetuation, which will develop their humanity. Thus, since the city exists for men to become human, that is its specific purpose. It is considered natural. That is to say, the ability to speak serves to enhance the process of becoming human.
Man can share ideas, thoughts, and feelings in reference to what is good or bad, right or wrong.
By talking about what is held to be just or unjust, man defines the limits and tolerances of the c ity and establishes rule. This discussion enables men to reach consensus on these issues. Thus, these agreements set the standard for what is acceptable and good for the given city. Speech, while distinguishing man from animals and thereby confirming his rule over them, furnishes men with the capability to make prudent decisions for themselves and those they rule. Without communication, the city would not function, resulting in chaos.