Oliver Twist; or, The Parish Boy’s Progress was Charles Dickens's second novel and was published in monthly parts in Bentley's Miscellany between 1837 and 1839. The novel is a major departure from Dickens's debut, The Pickwick Papers, which is more like a series of comic sketches than a novel. The Pickwick Papers closely resembles the sporting stories of Robert Smith Surtees, Jorrocks' Jaunts and Jollities or Mr. Sponge's Sporting Tour. Oliver Twist, published only the following year, is already an entirely different type of book. It is more melodramatic and sentimental than Dickens's later novels, but the moral seriousness, the tone, and the themes that characterize his mature work are already present.

In particular, the figure of the innocent, exploited child is central to the book. Critics have often pointed out that Oliver himself is profoundly unrealistic. He is never corrupted and never seems to understand the evil natures and motives of those around him. Even the way he speaks marks him out from other parish boys and pickpockets. George Orwell remarks that all the "good" children in Dickens—Biddy Wopsle, Lizzie Hexam, Sissy Jupe, and Little Dorrit—mysteriously speak upper-class English despite having working-class origins, and this is a tradition which clearly begins with Oliver Twist. This aspect of Oliver's idealized character is particularly marked when he goes to work for Mr. Sowerberry. His way of speaking and his manners are obviously superior to those of Noah Claypole and even the Sowerberrys themselves. There is an irony in the subtitle of the novel, The Parish Boy's Progress, since Oliver never progresses or changes at all. In Dickens's view, he never needs to do so.

Dickens was to spend much of his career railing against the cruelty and corruption of numerous English institutions from boarding schools to the law courts, and it is institutional violence that preoccupies him in Oliver Twist. Although some of the most memorable scenes concern the terrifying Bill Sykes and the sinister Fagin, Dickens does not condemn these career criminals with the same bitterness as the workhouse authorities and the parish authorities, which, even when Oliver is a baby, conspire to cheat him of the small sums allowed for his upkeep and make him the "victim of a systematic course of treachery and deception." Although he quite frequently allows himself such vehement expressions to describe the cruelty of the parochial authorities, Dickens's favorite weapon is irony, which he employs thickly and frequently throughout the book. He is particularly scathing about those whose business is charity and who nonetheless display thoroughly uncharitable natures, as when he writes of the workhouse and its administrators:

The members of this board were very sage, deep, philosophical men; and when they came to turn their attention to the workhouse, they found out at once, what ordinary folks would never have discovered—the poor people liked it! It was a regular place of public entertainment for the poorer classes; a tavern where there was nothing to pay; a public breakfast, dinner, tea, and supper all the year round; a brick and mortar elysium, where it was all play and no work.

When Dickens was writing, the Poor Law of 1834 had just forced a large number of able-bodied people living in poverty to enter the workhouses, since they received no subsistence allowance unless they did so. Dickens, therefore, uses Oliver Twist as a vehicle for biting social commentary about the treatment of the poor. However, as always in Dickens's works, the principal problem with the system is that it is run by corrupt and unfeeling people. Dickens treats his principal institutional culprit with an appropriate lack of ceremony. While Fagin's last night alive is the subject of some pathos, Mr. Bumble's fate is merely ridiculous. The hen-pecked husband was a stock figure of nineteenth-century literature, and Mr. Bumble's humiliating subjection to his wife is described in some detail immediately before the more dignified demise of Fagin. Both Bumbles are then dispatched with a brief, crushing paragraph in the final chapter:

Mr. and Mrs. Bumble, deprived of their situations, were gradually reduced to great indigence and misery, and finally became paupers in that very same workhouse in which they had once lorded it over others. Mr. Bumble has been heard to say, that in this reverse and degradation, he has not even spirits to be thankful for being separated from his wife.

This final chapter emulates Jane Austen, along with numerous earlier models, in speedily tying up numerous loose ends and informing the reader of the final destinies of various characters, including Oliver, who finally gains a father when Mr. Brownlow adopts him. Anthony Trollope, parodying Dickens as "Mr. Popular Sentiment" in The Warden, clearly had such conclusions as this in mind when he complained of Dickens's bad characters being impossibly bad, while his good characters were angels in human form. Oliver is certainly angelic, but for a sentimental description of perfection it would be difficult to surpass Dickens's final vision of Rose:

Rose Maylie in all the bloom and grace of early womanhood, shedding on her secluded path in life soft and gentle light, that fell on all who trod it with her, and shone into their hearts.

If Rose is like an angel, or a fairy, it is only appropriate that Oliver Twist ends like a fairy story. As one of Dickens's chief detractors, Oscar Wilde, put it in The Importance of Being Earnest, the good ends happily, and the bad unhappily—that is what fiction means. Even more sympathetic critics have not been slow to point out the book's flaws: its flat characters, melodramatic language, heavy use of irony, and sentimental treatment of women and children. It is clear that Oliver Twist has many of the characteristic faults of Dickens and of the Victorian novel in general. It is less clear just what it is that saves the book from being a failure. Part of the answer must surely be the energy and vitality with which Dickens writes. His cliffhangers may be lurid and sensational, but the suspense is real. Dickens probably would not have been particularly insulted by the comparison with a fairytale: a vivid and engaging story which keeps the reader turning pages and suspending disbelief through sheer vigor.