The writer expresses deep gratitude for the comforting letter and verses received, highlighting the emotional balm they provided. He recounts a painful experience with Jean-Jacques Rousseau, who, through manipulation and deceit, incited public opposition against them in Geneva, causing financial loss and personal distress. The writer underscores Rousseau’s hypocrisy and ingratitude, contrasting his actions with his own efforts and commitment to literary and personal integrity. He affirms his admiration for the recipient’s military and literary accomplishments, pledging lasting esteem and support.