The letter presents a plan for a citadel designed by Détalonde Morival, whose rapid progress in mathematics and engineering is described as extraordinary. The author criticises complex mathematical pursuits as unnecessary, emphasising the practical value of a good engineer over abstract calculations. The letter advocates for Morival, a noble and capable soldier, to be employed in the service of the sovereign, highlighting his skills, dedication, and loyalty. The author, nearing the end of his life, seeks comfort in the sovereign’s continued support for Morival, asserting that such support would be a just response to the injustices Morival has faced. Additionally, according to T. D. N. Besterman, the letter is certainly dated 2 January 1775.

The letter discusses efforts to secure support for the officer Morival, highlighting his dedication and unwavering resolve to serve the sovereign. The author aligns his views with those of the sovereign, reflecting on the importance of strong defense and the broader impact of the decisions made by rulers. He also mentions the admiration expressed for the sovereign in the letters of Lord Chesterfield, noting their significance due to Chesterfield’s reputation for grace and sincerity. The letter concludes with the author expressing his enduring desire to please the sovereign, tempered by the humility that comes with age.

The author, hindered by age-related ailments, expresses gratitude to the sovereign for a letter filled with beautiful verses, acknowledging his inability to reciprocate in kind. He praises the young officer Morival, who has made remarkable progress in his military skills and continues to serve with dedication. The author argues that Morival’s case, unjustly handled in his absence, should be reviewed rather than seeking a pardon, as this would imply guilt. The letter concludes by commending the sovereign for protecting an innocent man and expressing the author’s deep respect and attachment as he nears the end of his life.

The author expresses profound gratitude for the king’s generous favours, which have brought joy to his final days. He admires the king’s literary talent and his protection of the oppressed Morival, while expressing disapproval of Morival’s pursuit of a pardon, deeming it demeaning. Instead, he emphasises Morival’s talents and loyalty as worthy of royal service. The author also reflects on his own commitment to remain in the Alps rather than returning to Versailles, expressing deep respect and regret at not having spent his final years in closer proximity to the king, whom he greatly admires. Furthermore, the day and month are in Voltaire’s hand, the year in Wagnière’s. According to T. D. N. Besterman, the letter is written in March 1775.

The author expresses deep concern for the King’s health, noting that the King’s well-being is of greater importance to the world than his own. He requests the King’s continued support for Morival, who seeks rehabilitation and the opportunity to serve more effectively. The author mentions an official declaration condemning the previous unjust judgement against the Chevalier de la Barre, which parallels his hope for justice for Morival. If unsuccessful in France, he suggests that Morival could serve in the Russian army, where conditions would be less barbaric than those of the troubling events in Abbeville. Additionally, according to T. D. N. Besterman, the letter is written in 1774.

The author expresses deep gratitude upon receiving a porcelain bust from the King, praising it as a nobler gift than any given by other monarchs. He mentions a new edition detailing the life of a celebrated figure who shared the King’s achievements, and suggests that Détalonde Morival could adeptly illustrate the King’s military campaigns due to his remarkable skill in drawing. He requests an extension of Morival’s leave, emphasizing Morival’s dedication and the impact of the King’s support. The author concludes with a reflection on the King’s dual roles as a hero in both war and philosophy, expressing lifelong appreciation.

In this letter, the writer returns Morival d’Etalonde, commending his commendable conduct and tactical expertise while highlighting the absurdity of his past condemnation. The writer praises the King for his legislative wisdom and protection of virtue, contrasting it with the continued barbarity and outdated laws in France. He reflects on his own literary works, criticizing the excesses of publishers and the persistence of past conflicts with critics. Ultimately, he implores the King to manage his literary legacy as he has done with so many others and acknowledges the transient nature of human achievements. According to T. D. N. Besterman, ‘In MS1, Wagnière subsequently added 1776, but of course there is no doubt that the letter was written in 1775.’