Dr. Moore published Zeluco in 1789. The opening line sets the tone of what is to follow: “Religion teaches, that Vice leads to endless misery in a future state; and experience proves, that in spite of the gayest and most prosperous appearances, inward misery accompanies her; for, even in this life, her ways are ways of wretchedness, and all her paths are woe.” Zeluco, despite being born into a prosperous family, fosters a cruel and selfish character that alienates him from everyone, resulting in a miserable marriage and a jealous mistress.

Beginning with Zeluco’s childhood, his initial cruelty is demonstrated when he strangles a bird who would not sing for him on demand. After losing his father at the age of ten, his mother permits him every indulgence. Locke argues that individuals learn by experience and that, as young children, we are a blank sheet on which impressions and ideas are written. Zeluco’s mother, by letting him indulge his cruel nature, fostered vice within him. Hobbes defined the state of nature as the fearful war of every man against each other. The passions which incline men to war are indignation, covetousness, jealousy, vainglory, and cruelty. With the killing of a bird, the reader has already seen he is capable of cruelty. Zeluco, with the help of his uncle, obtains a commission in the Spanish army and is sent to Cuba, but he abuses his men and does not achieve the glory he seeks. After returning home, he coversts the wife of his Portuguese neighbor. When he tries to seduce her but fails, he spreads a rumour that he is the father of her unborn child, trying to provoke a jealous reaction from her husband. As Hobbes suggests, Zeluco is constantly at war with his fellow man, leading to an unhappy and miserable life despite his financial independence and extravagant lifestyle.

The novel is also renowned for its social commentary on the slave trade. It was several years before eighteenth-century society recognised the immorality of the slave trade, only became a public concern in the second half of the century. Locke said slavery was unjust, as no man has a right over another. Zeluco inherits a plantation in Cuba, and a slave dies due to his cruelty. New laws were not enacted for the protection of slaves, as it was believed a humane master would never be unjust or injure a person, just as a bad master protects people out of self-interest. When Zeluco discusses this matter with the physician and asks if he has a right to do with the slaves as he pleases, the physician replies that he doubts these rights could ever be proved. Zeluco argues slavery is authorised by the Bible (Colossians 3:22 ‘Saves obey your earthly masters in everything’). The physician counters with The Sermon on the Mount, pointing out that charity, benevolence, and mercy are also authorised. Zeluco asks if blacks are equal to whites, and the physician replies that they are only different. In a century where anything that went against the dominant ideology was regarded as inferior, to be seen as equal and different is significant.

The other aspect of Moore’s work is religious intolerance in a society where Catholicism was associated with the corrupt, foreign, and revolutionary. When a Roman Catholic priest is summoned to the dying slave, Hanno, to deliver the last rites, he is more concerned with making sure Hanno accepts Catholic doctrine than if he has been a good man. Hanno forgives the cruel Zeleco and hopes he will not suffer in hell forever, which the Catholic priest deems heresy. Presumably, a slave cannot forgive a master, and it is only the divine will that can decide on punishment. This emphasizes Moore’s complaint that Catholicism adheres to the letter of the law and not the spirit. Moore also highlights the religious divide in Laura’s family. Her father is a German Protestant, and her mother is an Italian Catholic. When they marry, they agree not to interfere in each other's religion, and any boy will be brought up as a Protestant and any girl will be a Catholic. Father Mulo wants the wife to convert the husband to Catholicism, and a zealous Calvinist wants the colonel to convert his wife to Protestantism. The wife objects to the suggestion, saying why should she bother her husband when he has never bothered her? Mulo claims the situations are not the same, as he would be leading her from truth to falsehood.

The structure of the story reflects the irony of the events. Zeluco wants to live a financially independent, carefree life, and with the death of his father and obtaining the remaining income from his mother, he is free to live a lavish lifestyle. However, although money and connections obtain him a commission in the army, he is not successful. Thus, wealth can buy him a commission, but it cannot buy the success or respect of his fellow officers. When he tries to seduce his Portuguese neighbour, she refuses him, and he starts a rumour that the baby she is carrying is his. Ironically, when Zeluco’s mistress Nerina hears of Laura’s pregnancy, she also starts a rumour that the baby does not belong to Zeluco but to Laura’s half-brother, Colonel Seidlit. This results in him strangling the child in a fit of rage, paralleling the death of the bird he killed as a child. Unlike the bird, he shows great remorse at the death of the child, but this is born out of pure self-interest, so he may be accused of his death. Equally, he shows concern for his wife, lest her testimony condemns him.

Ironically, in a sitting room, there is a picture which stands as testimony to his guilt entitled Massacre of the Innocents, where a child is being strangled by a soldier. The Colonel states that the soldier looks like Zeluco and pencils his name on the picture to provoke him. When Zeluco demands satisfaction, Carlostein claims responsibility to protect Laura’s brother. Due to her jealousy of Laura Nerina suggests Zeluco could easily be free of his wife with an overdose of laudanum, but Zeluco does not understand her meaning. Ironically the evening before the duel, Zeluco goes to see his misters and finds her in bed with another man. As he draws his sword, the lover stabs him with a stiletto, and it is he who dies a few days later from his injuries. Instead of claiming his revenge on what he sees as his wife’s unfaithfulness, he dies himself. This now frees Laura from a loveless marriage and, after a period of mourning to marry Carlostein.

Despite its huge popularity when first published and critical acclaim by the critics, this novel has largely been ignored over the proceeding centuries.