What it is
De Officiis — "On Duties," or, more literally, "On Obligations" — is a three-book treatise in epistolary form, addressed by Cicero to his son Marcus, then a student in Athens. The work was dictated rapidly in October and November 44 BCE, in the months after the assassination of Julius Caesar and during Cicero's public opposition to Mark Antony, and was completed before Cicero's own murder thirteen months later. Books I and II draw heavily on a (now lost) treatise on duty by the Stoic Panaetius; Book III is mostly Cicero's own. It is the densest surviving ancient statement of what a Roman senator, magistrate or citizen owed to the Republic.
Historical context
The composition was a deliberate political act. Cicero had returned to Rome after the Ides of March hoping for a constitutional restoration; he had instead found a city in which Antony, holding the consulship, was systematically dismantling the conditions for one. De Officiis was written under those threats and dispatched to Marcus partly as a father's instruction and partly as a public statement. Read this way, the recurring discussion of honestum and utile — of the honourable and the apparently advantageous — is not abstract: it is Cicero, eyes on Antony, saying that a man who would sacrifice the Republic to his own advancement has misunderstood his own advantage.
What it argues
The book is organised around three Latin terms it keeps returning to. Honestum is the honourable, what is right in itself — the ethical substance the Stoic tradition organises the moral life around. Utile is the advantageous, what serves one's own or one's faction's interest. Officium is duty, the practical action that follows from one's role and obligations. The book's central argument, set out at length in Book III, is that honestum and utile are never genuinely opposed: the apparent conflict between them is a sign that utile has been wrongly conceived. To act dishonourably for one's own advantage is to misunderstand what one's own advantage actually is.
Book I takes up the four cardinal virtues — wisdom, justice, greatness of soul, decorum — and applies each to specific duties of public life. Book II treats the duties whose subject is utile, on the Stoic premise that what is genuinely useful coincides with what is honourable. Book III handles the apparent conflicts case by case (Regulus returning to Carthage; the sale of the Rhodian grain) and gives the synthesis.
Why it has been read for two millennia
The European moral tradition's vocabulary for talking about public duty is largely Cicero's. Ambrose's De Officiis Ministrorum took the framework into the Christian moral life (replacing the Stoic foundation with a Christian one but keeping the structure). Aquinas drew on Cicero in the Summa. The humanist schools of the Renaissance taught De Officiis as a moral primer. Erasmus, Melanchthon, the Reformation and Counter-Reformation educators continued to. Locke and the American founders read it: Benjamin Franklin reports having internalised it as a young man; John Adams cites it across the Defence of the Constitutions. It is one of the small handful of ancient texts whose influence on the Western moral imagination is hard to overstate.
Citing De Officiis
Standard citation is by book and section (e.g. Off. 1.20). The standard Latin text is the Oxford Classical Texts edition of Cicero's philosophical works; see our Sources page for the public-domain translations and digital archives we work from.