Changing Times
The novel is set in the years before the Second World War at the twilight of a time of rampant gang violence. As Greene himself said of the story and its context, that world of despair and desperation has since passed, fortunately. Pinkie is the leader of a gang in decline; although we do not hear too much about Kite, the former leader and Pinkie's mentor, we can assume that he was not like Mr. Colleoni, a rival gangster who represents the new businessman-like breed of criminal who reaches a kind of social compromise with the police. It is precisely because Pinkie's type is in the process of becoming an anachronism that his story gains such pathos.
Deception
Throughout the novel, Pinkie is a rather despicably devious character that does not shy from lying (or killing people) in order to accomplish his pragmatic aims as a gangster; his entire relationship with Rose, for example, is premised on using the lie of loving her in order to silence her. However, other characters have their own, perhaps less direct, associations with deception. Charles Hale, at the beginning of the story, travels around under an alias for the sake of the newspaper sweepstakes; also, out of his personal inclination, he tells people he does not know that his name is "Fred."
Music
Pinkie and Ida are archenemies to each other, and one of the ways their opposite characters are most clearly delineated is their relationships to music. Ida is introduced as singing in a pub with a warm and mellifluous voice; the all-encompassing nature of music is one of the best symbols for her own all-encompassing, and often overwhelming, personality. Pinkie, on the other hand, feels threatened by the uncanny and unmanning influence that music has over him; an analog of sexuality, it is something that can give him comfort but which he fears because it deprives him of his heightened state of stress that makes him so violently capable.
Catholicism
Pinkie and Rose, as the two Roman Catholics of the novel, stand in opposition to the highly secular Ida Arnold and the world of simple, accommodating morals that she represents. Not coincidentally, they also belong to the lower classes of their society in Brighton; the blatant and traumatic exposure that Pinkie has to his parents having intercourse, and his subsequent religious-inflected revulsion against it, comes from the squalor of their living conditions. Catholic belief—with, as Greene seems to understand it, its greater emphasis on religion and morality as distinct, and often highly critical against worldly society—at once distances these two characters from their society and provides them with a way of understanding the alienation that has been imposed upon them as poor outcasts.
Violence and Sexuality
As a gangster, Pinkie assumes that the only standard by which he will be judged is his toughness, understood as his willingness to engage in violence. This presumably would allow him, even at the tender age of seventeen, to gain recognition as an equal from older gang members; in an important sense, it would redeem the suffering and trauma he went through as a younger child, since it is on the basis of that hurt that he has such sociopathic capability to harm others. However, as he discovers, sexuality (specifically, heterosexuality) is the standard by which most people judge maturity. This is highly frustrating to him since much of his childhood trauma has to do with witnessing his parents engaging in intercourse, and his Catholic belief makes him regard sex as a sin. The only thing he can do is further indulge his violent inclinations to get away from this confusion with sex.
Masculinity
One could say that the central conflict of the story is Pinkie's -- the Boy's -- quest to attain manhood. Pinkie—whose path to being recognized as a mature adult has been laid not by his family or a stable social environment but rather by Kite, the late leader of Pinkie's gang—sees power through violence and heartless manipulation as the only way to be a man in the squalid, dangerous, and despairing context of underclass Brighton. Other characters, meanwhile, challenge this worldview of his with their alternate perspectives on life and especially what it means to be a man; they encourage him to drink, marry, and have sex.
Friendship
One of the most important relationships in the novel is only mentioned a few times, though it propels the entire plot and provides the basis for Pinkie's otherwise seemingly exaggeratedly sociopathic and evil personality: Pinkie's friendship with Kite. The plot could be summarized as Pinkie's vendetta for the loss of Kite, who was a mentor, older brother, and father, where Pinkie had no one else. Since Pinkie felt such revulsion for his parents making love in front of him -- though this is precisely the act that produced him in the first place -- he effectively lacked a basis for his own identity until Kite practically adopted him into the gang and provided him with a model of what a man could be. Thus, once Kite died, Pinkie again lost his sense of personality and had to become the lost friend.
