Warning: Wikipedia contains spoilers
It was considered by many literary critics and reviewers to be controversial when first published in 1984, due to its depiction of extreme events, which although perhaps not particularly graphically violent were gruesome in that they involved a child killing another (three to be exact). These scenes are remembered by the narrator rather than portrayed directly, and with hindsight may be judged as no more inappropriate than the death of Piggy in The Lord of The Flies. The description of events is both frank and matter of fact: this calm and detached form underscores the very mundanity of the evil which Banks is writing about.
The narrator's psychopathic brother, Eric, what he does, and what happened to him to precipitate his plunge into utter insanity is, however, an altogether darker and explicitly nastier proposition.
The novel, it can be fairly safely said, works largely from the position of grand guignol, yet it acts on a number of levels. That this is a political novel wrapped up ostensibly in the form of a horrific bildungsroman is indisputable: it was written during the bleaker years of the Thatcherite reinvention of Britain as a corporate plc. The miners strikes, unemployment, cutbacks in social services and healthcare, and generally the rollback of the welfare state were cutting what seemed to many people a grim swathe through the country. Banks, an acute and sensitive writer with an unerring finger on the pulse of things, explores the situation with a caustic eye. The first paragraph of Chapter Four makes the political dimension to the novel explicit:
The novel further orients itself around the nature of power and about the abuse of power. The deception of Frank by his father, one of Banks' central themes, (a concept dealt with more fully in The Crow Road), and the blind propensity of individuals to self-deception, are accentuated in the final chapters of the book when new facts which are brought to the narrator's attention overthrow much of what has been said before, and the reader is forced to completely re-assess the opinions formed about the narrator.
It is not, as one may readily discern, an easy novel to read, but for all its manifest flaws is perhaps the finest and most thoughtful British novel of the last quarter of the 20th century.