De Officiis (On Duties or On Obligations) is a political and ethical treatise by the Roman orator, philosopher, and statesman Marcus Tullius Cicero written in 44 BC. The treatise is 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 (Book I), what is to one's advantage (Book II), and what to do when the honorable and one's private interest apparently conflict (Book III). In the first two books Cicero was heavily influenced by the Stoic philosopher Panaetius, but wrote more independently for the third book. In addition to being a central component of liberal education for centuries, the work was held in high regard among many prolific philosophers and statesman including Augustine, Thomas Aquinas, Hugo Grotius, Montesquieu, Voltaire, and the American Founding Fathers. De Officiis, along with Xenophon's Cyropaedia, are considered among the foundational works in the genre of the mirrors for princes, now most famously associated with Machiavelli's The Prince. Background De Officiis was written in October–November 44 BC, in under four weeks. This was Cicero's last year alive, and he was 62 years of age. Cicero was at this time still active in politics, trying to stop revolutionary forces from taking control of the Roman Republic. Despite his efforts, the republican system failed to revive even upon the assassination of Caesar, and Cicero was himself assassinated shortly thereafter. Writing De Officiis is written in the form of a letter to his son Cicero Minor, who studied philosophy in Athens. Judging from its form, it is nonetheless likely that Cicero wrote with a broader audience in mind. The essay was published posthumously. Although Cicero was influenced by the Academic, Peripatetic, and Stoic schools of Greek philosophy, this work shows the influence of the Stoic philosopher Panaetius. Panaetius was a Greek philosopher who had resided in Rome around eighty years previously. He wrote a book On Duties () in which he divided his subject into three parts but had left the work unfinished at the third stage. Although Cicero draws from many other sources, for his first two books he follows the steps of Panaetius fairly closely. The third book is more independent, and Cicero disclaims having been indebted to any preceding writers on the subject. Michael Grant tells us that "Cicero himself seems to have regarded this treatise as his spiritual