Conformity
The characters in Never Let Me Go place a cultural premium on conformity––for example, Kathy repeatedly emphasizes how "typical" she is, and Ruth blatantly copies the gestures of older students at the Cottages. The organ donation system seems to run relatively smoothly because everyone is willing to accept docilely their fate as donors. Conformity is a common topic for dystopian science fiction novels like Never Let Me Go, but Ishiguro is unusual in that he does not suggest a better alternative to conformity. With the exception of Tommy's brief tantrum in the field, no character indulges in any act of rebellion, large or small. The novel's universe is one in which conformity is an immutable quality of human nature.
Willful ignorance
Ishiguro highlights many forms of willful ignorance, of social issues (like the organ donations) as well as personal issues (like sex and virginity). Often, his characters shy away from pressing for information when they sense they do not want to know the answers to their questions. He suggests that willful ignorance is the mechanism by which social injustices are perpetuated.
Free will
The clones are unable to change their fates as organ donors, but their lack of free will affects many other elements of their lives as well. For example, Ruth never achieves her dream of working in an office, and Kathy gets precious little time with Tommy. Ishiguro is ambiguous about where this lack of free will comes from––because Ruth never tries to work in an office, we never learn whether her unhappy life is due to the system or her own lack of initiative.
Communication
Part of the novel's heart-breaking, elegiac ending can be attributed to the characters' failure to communicate. Communication failures factor into pivotal moments in the plot, such as Ruth's mocking of Tommy's drawings. However, there are also barriers to communication that lie beyond the characters' control; for example, Ruth never finds out whether her plan to reunite Kathy and Tommy worked.
Hope
Ishiguro's outlook on hope is highly conflicted. It may make people feel better and allow them to live "decent lives"; the clones are happier at the Cottages because they have the idea that they can apply for deferrals if they wish, a rumor that Miss Emily allows to exist because it gives people hope. Nevertheless, in the novel's universe, hope only comes from falsehoods and delusions, from Kathy's hope that Ruth will break up with Tommy, to the illusive hope offered by the imagined deferral program.
The individual's obligation to society
The organ donation program is premised on the idea that the clones owe their lives to society, and should be prepared to sacrifice them. This principle––not the actual donation program––is the novel's real point of interrogation. Madame explores this notion when she tries to explain to Tommy and Kathy that they should be happy they had happy lives at all, given that so many clones did not.
Playing God
The most common objection raised to cloning and genetic engineering, both in Never Let Me Go and in general, is that it involves playing God. In the novel, Ishiguro explores other ways that individuals might play God: arguably, the clones who try to change their fates are playing God as much as the scientists who created them in the first place.
