To complete this lesson, complete the following tasks:
1. Study the lesson for mastery.
2. Complete the lesson assessment.
But having resolved at this time to write to you somewhat, and a great deal in time to come, I have thought proper to set out with that subject which is best adapted to your years and to my authority. For, while many subjects in philosophy, of great weight and utility, have been accurately and copiously discussed by philosophers, the most extensive seems to be what they have delivered and enjoined concerning the duties of mankind; for there can be no state of life, amidst public or private affairs, abroad or at home — whether you transact anything with yourself or contract anything with another — that is without its obligations. In the due discharge of that consists all the dignity, and in its neglect all the disgrace, of life.
This is an inquiry common to all philosophers; for where is the man who will presume to style himself a philosopher, and lay down no rules of duty? But there are certain schools which pervert all duty by the ultimate objects of good and evil which they propose. For if a man should lay down as the chief good, that which has no connexion with virtue, and measure it by his own interests, and not according to its moral merit; if such a man shall act consistently with his own principles, and is not sometimes influenced by the goodness of his heart, he can cultivate neither friendship, justice, nor generosity. In truth, it is impossible for the man to be brave who shall pronounce pain to be the greatest evil, or temperate who shall pi’opose pleasure as the highest good.
Though these truths are so self-evident that they require no philosophical discussion, yet they have been treated by me elsewhere. I say, therefore, that if these schools ares elf-consistent, they can say nothing of the moral duties. Keither can any firm, permanent, or natural rules of duty be laid down, but by those who esteem virtue to be solely, or by those who deem it to be chiefly, desirable for its own sake. The teaching of duties, therefore, is the peculiar study of the Stoics, of the Academics, and the Peripatetics; because the sentiments of Aristo, Pyrrho, and Herillus, have been long exploded. Yet even those professors would have been entitled to have treated upon the duties of men, had they left us any distinction of things, so that there might have been a path open to the discovery of duty. We shall, therefore, upon this occasion, and in this inquiry, chiefly follow the Stoics, not as their expositors, but by drawing, as usual, from their sources, at our own option and judgment, so much and in such manner as we please. I therefore think proper, as my entire argument is on moral obligation, to define what a duty is, a definition which I am surprised has been omitted by Panoetius; because every investigation which is rationally undertaken, concerning any subject, ought to set out with a definition, that it may be understood what is the subject of discussion.