As in Book I, Cicero continues to examine duty, or appropriate action, but in this book, he discusses actions which pertain to utility, rather than honorableness. Things that are utile "protect human life," and are associated with the private good (90). Some utile things are inanimate (i.e. natural resources), while others are animate (i.e. livestock, human beings, and the gods). Each of these utile things must be interacted with in such a way as to elicit their cooperation in preserving human life. For inanimate objects, this means practices like land cultivation and architecture. For humans, it means gaining the devotion of others to ourselves.

To "entice and arouse the devotion" of others for "our own utility," one should act out of goodwill, honor, or trust-building in fellow man, rather than in a self-serving way (94). These things can be done through justice, one Cicero's four virtues. Justice, Cicero explains, is necessary not only for those in high political office, but in every kind of human interaction, whether farmers or thieves. Just actions will foster respect and esteem, rather than fear. Cicero warns that to rule by fear breeds a hatred of the ruler, as well as a constant fear within the ruler that they may be killed or overthrown at any moment.