"There is no part of life, neither public nor private, neither forensic nor domestic, neither in how you conduct yourself nor in your dealings with others, when is it possible to be free from appropriate action." 

Cicero does not limit the application of duty to the public nor private sphere. He repeatedly emphasizes that one should conduct oneself in private just as they do in public. Lack of visibility does not, for Cicero, relinquish one's accountability. 

"He who holds the highest good to have no connection to virtue, and measures it by his own advantage, not by honorableness…cannot cultivate friendship, justice, or liberality."

In contrast to the Epicureans, who believed that what brought physica pleasure constituted the highest good, Cicero believes that the highest good comes from virtue, or the mind. Virtuous actions adhere to hisprincipals of honorableness. 

"There is also another division of appropriate action: what is called a sort of 'ordinarily' appropriate action and an 'entirely' appropriate one." 

An ordinarily appropriate action can be carried out by anyone who is relatively good, while an entirely appropriate action accounts for both honorableness and usefulness. For Cicero, a person capable of appropriate action conducts themselves according to virtue, which would prohibit them from ever making a disgraceful decision.