The science of human cloning is not the primary concern of Never Let Me Go, and Ishiguro takes artistic license with some of the details of how humans are cloned in his novel. Nevertheless, many of his questions about the ethics of human cloning are ones that have been raised and debated in real life.
These ethical questions first came to the popular consciousness in the 1960s and 1970s, when stem-cell research was first beginning to be conceived, and human cloning began to look like a real possibility. The scientists Joshua Lederberg and James D. Watson wrote articles in The American Naturalist and The Atlantic Monthly, respectively, arguing that cloning was dehumanizing and could result in unforeseen ethical problems. Ishiguro's novel could arguably be read as a rejection of the notion that cloning is dehumanizing; indeed, the purpose of Hailsham is to convince the public that the clones are human.
More recently, scientists and the public have made efforts to distinguish between "therapeutic cloning"—that is, the cloning of cells and tissues to help cure diseases––and "reproductive cloning," which would involve creating “whole” individuals. Many countries, including the United Kingdom and the United States, allow therapeutic cloning, although there is continuing debate, especially in the U.S., about whether the federal government should fund it. Ishiguro's novel merges the two; reproductive cloning is pursued for therapeutic purposes.