The Black Prince begins and ends with a domestic quarrel between a married couple. During the novel, Murdoch analyzes the institution of marriage by looking at it through three different couples. For each of these couples, marriage fails. Furthermore, in two of the marriages, Priscilla's and Roger's, and Rachel's and Arnold's, the marriage proves fatal; one of the partners is dead by the end of the book. Given the failure of marriages in her novel, Murdoch suggests that it is a consistently painful institution, which might be better avoided. Bradley Pearson himself articulates a similar perspective when he suggests that the state of being married is inconsistent with a human's natural desire and that marriage generally leads one towards a state of perpetual loneliness.
Hamlet is major motif in the novel. Hamlet's characters, text, and themes recur several times. The play primarily appears because Julian Baffin wants to study Hamlet, so she keeps asking Bradley to teach it to her. By explaining it to Julian, Bradley is able to articulate his interpretation of what Hamlet actually means. The theme in Hamlet that is most important to The Black Prince is that of identity and the ability to create one's identity through the use of words. As Bradley Pearson writes his narrative, he struggles with this issue, which may be the reason for which the novel is called The Black Prince—a title usually given to Hamlet. Hamlet's appearance in the novel also plays an important role in the growing rapport between Julian and Bradley, since their initial tutorial is a symbolic sex scene, and when Julian eventually dresses up as Hamlet, Bradley proceeds to make violent love to her. Murdoch's frequent references to Hamlet also indicate her textual allegiance to Shakespearian techniques, which she greatly admired.
Attention to Julian's feet is a motif that chronicles the sexual awakening of Bradley. The motif begins when Bradley sees Julian walking barefoot by the subway station. He proceeds to buy her a pair of purple boots, but not before his socks tumble out of his pocket and she puts them on. It is when she finally puts on the boots in the store, that Bradley feels his first swell of lust. Later during their Hamlet tutorial, Julian arrives wearing the same purple boots. As the room grows hot, she asks if she can take them off. She asks Bradley if her feet smell and he says that they do, but that he finds it "charming". As lust and unrealized love overwhelm him, Bradley comments that he could smell "her sweat, her feet, her breasts." Julian's exposure of her feet galvanizes Bradley's sexuality and serves as one of the symbolic steps towards the awakening of his love.