The survey of the passions begins with an account of Natura's birth of well-to-do but not extraordinary parents, his mother's death, and his father's second marriage, his attack of the small-pox, his education at Eton, and his boyish love for his little play-mate, Delia. Later he becomes more seriously compromised with a woman of the streets, who lures him into financial engagements. Though locked up by his displeased father, he manages to escape, finds his lady entertaining another gallant, and in despair becomes a regular vagabond. Just as he is about to leave England, his father discovers him and sends him to make the grand tour under a competent tutor. In Paris the tutor dies, and the young man is left to the exercise of his own discretion. Benighted in a wood, he finds shelter in a monastery of noble ladies, where both the abbess and her sister fall in love with him. After fluctuating between the two, he tries to elope with the sister, is foiled by the abbess, and sets off again upon his travels. In Italy he hears of his father's difficulties and starts for home, but enters the French service instead. He is involved with a nobleman in an attempt to abduct a lady from a nunnery, and would have been tortured had not the jailor's wife eloped with him to England. There he enters Parliament and is about to contract a fortunate marriage when he incautiously defends the Chevalier in conversation, fights a duel, and, although his antagonist is only wounded, he finds his reputation blighted by the stigma of Jacobitism. After a long illness at Vienna where he is pestered by Catholic priests, he recovers his health at Spa, and falls in love with a young English girl. Her parents gladly give their consent, but Maria seems unaccountably averse to the match. And when our hero is assaulted by a jealous footman, he perceives that the lady has fixed her affections on a lower object. Natura on his return to England prospers and marries happily, but his joy is soon destroyed by the death of his father and of his wife in giving birth to a son. Consumed by ambition, the widower then marries the niece of a statesman, only to discover what misery there is in a luxurious and unvirtuous wife. Natura soon experiences the passions of melancholy, grief, and revenge. His son dies, and his wife's conduct forces him to divorce her. In the hope of preventing his brother from inheriting his estate he is about to marry a healthy country girl when he hears that his brother is dead and that his sister's son is now his heir. Thereupon he buys off his intended bride. At his sister's house he meets a young matron named Charlotte, for whom he long entertains a platonic affection, but finally marries her and has three sons. Thereafter he sinks into a calm and natural decline and dies in his sixty-third year.