Cicero's style is a key to the success of De officiis, and not just the literary style, but the political and intellectual style. Regulus aside, the demands of duty generally stretch only as far as the well-educated, well-to-do man is likely to follow. Thus, he insists, in a famous metaphor that Machiavelli later stood on its head, that courage is necessary but the courage of a human being is not the ferocity of the lion, just as wisdom is necessary but the intelligence of the human being is not the cunning of the fox.

On Politics: A History of Political Thought: From Herodotus to the Present (2012) - Ch. 4 : Roman Insights: Polybius and Cicero