The text is a precursor to the literary genre of the episodic picaresque novel, in which Quevedo, Rabelais, Boccaccio, Cervantes, Voltaire, Defoe and many others have followed. It is an imaginative, irreverent, and amusing work that relates the ludicrous adventures of one Lucius, a virile young man who is obsessed with magic. Finding himself in Thessaly, the "birthplace of magic," Lucius eagerly seeks an opportunity to see magic being used. His overenthusiasm leads to his accidental transformation into an ass. In this guise, Lucius, a member of the Roman country aristocracy, is forced to witness and share the miseries of slaves and destitute freemen who are reduced, like Lucius, to being little more than beasts of burden by their exploitation at the hands of wealthy landowners.
The Golden Ass is the only surviving work of literature from the ancient Greco-Roman world to examine, from a first-hand perspective, the abhorrent condition of the lower classes. Yet despite its serious subject matter, the novel remains imaginative, witty, and often sexually explicit. Numerous amusing stories, many of which seem to be based on actual folk tales, with their ordinary themes of simple-minded husbands, adulterous wives, and clever lovers, as well as the magical transformations that characterize the entire novel, are included within the main narrative. The longest of these inclusions is the tale of Cupid and Psyche, encountered here for the first but not the last time in Western literature.
Apuleius' style is innovative, mannered, baroque and exuberant, a far cry from the more sedate Latinity familiar from the schoolroom. In the introduction to his translation of The Golden Ass, Jack Lindsay writes:
Let us glance at some of the details of Apuleius' style and it will become clear that English translators have not even tried to preserve and carry over the least tincture of his manner... Take the description of the baker's wife: saeva scaeva virosa ebriosa pervicax pertinax... The nagging clashing effect of the rhymes gives us half the meaning. I quote two well-known versions: "She was crabbed, cruel, cursed, drunken, obstinate, niggish, phantasmagoric." "She was mischievous, malignant, addicted to men and wine, forward and stubborn." And here is the most recent one (by R. Graves): "She was malicious, cruel, spiteful, lecherous, drunken, selfish, obstinate." Read again the merry and expressive doggerel of Apuleius and it will be seen how little of his vision of life has been transferred into English.
Lindsay's own version is: "She was lewd and crude, a toper and a groper, a nagging hag of a fool of a mule."
Sarah Ruden's recent translation is: "A fiend in a fight but not very bright, hot for a crotch, wine-botched, rather die than let a whim pass by – that was her."
Apuleius' vocabulary is often eccentric and includes some archaic words. However, S. J. Harrison argues that some archaisms of syntax in the transmitted text may be the result of textual corruption.
In the last book, the tone abruptly changes. Driven to desperation by his asinine form, Lucius calls for divine aid, and is answered by the goddess Isis. Eager to be initiated into the mystery cult of Isis, Lucius abstains from forbidden foods, bathes and purifies himself. Then the secrets of the cult's books are explained to him and further secrets revealed, before going through the process of initiation which involves a trial by the elements in a journey to the underworld. Lucius is then asked to seek initiation into the cult of Osiris in Rome, and eventually becomes initiated into the pastophoroi, a group of priests that serves Isis and Osiris. Whether this religious ending is to be taken seriously or comically is a moot question in the interpretation of the novel.