Jefferson addresses Thomas Jefferson Smith at the request of Smith’s father, offering guidance intended to influence the young man’s conduct as he grows older. He urges him to honour God and his parents, care for his neighbours and country, and act with justice and honesty. The letter presents these principles as foundations for a morally responsible life and reflects Jefferson’s concern with character, duty and personal behaviour.

Jefferson supplements this advice with a poetic description of a virtuous person and a “Decalogue of Canons for observation in practical life”. These ten rules emphasise diligence, self-reliance, financial restraint, modesty, willingness, perspective and control of anger. They include advice not to postpone necessary work, not to spend money before receiving it, and to pause before speaking when angry. Taken together, the letter combines moral counsel with practical habits intended to guide everyday decisions and personal relationships.