A summary of intent of practicality in Bk.I[I]: (This approach is justified by the book’s opening passages; written to his son to guide him on his education, which is an achievement of life, and not merely its underlying theory).
Duty, which defines what we must do with our lives, can be reduced into its essential elements: profit and honesty, and their interaction. Everything that we do, we do because it is of benefit and because it is honest. Honesty is difficult to define purely, and any attempt can only be as a direction. For instance, if we look at what characterizes us as human beings to ourselves, we include our rationality, our sense of beauty, and our sense of honesty, which is some desire for a beautiful regularity to be kept pure in ourselves and (if we could choose it) in all else too (IV).
Although a definition of honesty is beyond capture, there are four “heads” by which, in an overlapping manner, honesty is manifested: (1) Prudence, which is the acquisition of truth; an inherently virtuous desire and activity, although it sometimes needs to be reminded that it is not an end unto itself, and taken to an extreme as a behavior it can lead to an abstinence from life. (2) Justice is our obligations to others…., by which one avoids harm to others, even if by passivity. This last is true since we do not exist only unto ourselves; a higher perspective sees that we are part of Nature. A useful rule of thumb is such that if there is doubt whether an action is honest or not, one should avoid it, since honesty generally shows itself, and doubt proves a preexisting suspicion (IX).
{XXI-XXVI don’t want Noting; they relate too specifically to Statecraft and War}
[I] “De Officiis is a treatise by Marcus Tullius Cicero divided into three books, in which Cicero expounds his conception of the best way to live, behave, and observe moral obligations. The work discusses what is honorable, what is to one’s advantage, and what to do when the honorable and private gain apparently conflict.” For further details see https://en.wikipedia.org/wiki/De_Officiis.
