juvenile novels, more than once a character looks with disdain at a student's choice of classwork, saying, "Why didn't you study something useful?" In Time Enough for Love, Lazarus Long gives a long list of capabilities that anyone should have, concluding, "Specialization is for insects." The ability of the individual to create himself is explored in stories such as I Will Fear No Evil, "—All You Zombies—", and "By His Bootstraps". Heinlein claimed to have written Starship Troopers in response to "calls for the unilateral ending of nuclear testing by the United States". Heinlein suggests in the book that the Bugs are a good example of Communism being something that humans cannot successfully adhere to, since humans are strongly defined individuals, whereas the Bugs, being a collective, can all contribute to the whole without consideration of individual desire. Sexual issues For Heinlein, personal liberation included sexual liberation, and free love was a major subject of his writing starting in 1939, with For Us, the Living. During his early period, Heinlein's writing for younger readers needed to take account of both editorial perceptions of sexuality in his novels, and potential perceptions among the buying public; as critic William H. Patterson has put it, his dilemma was "to sort out what was really objectionable from what was only excessive over-sensitivity to imaginary librarians". By his middle period, sexual freedom and the elimination of sexual jealousy became a major theme; for instance, in Stranger in a Strange Land (1961), the progressively minded but sexually conservative reporter, Ben Caxton, acts as a dramatic foil for the less parochial characters, Jubal Harshaw and Valentine Michael Smith (Mike). Another of the main characters, Jill, is homophobic, and says that "nine times out of ten, if a girl gets raped it's partly her own fault." According to Gary Westfahl, In books written as early as 1956, Heinlein dealt with incest and the sexual nature of children. Many of his books including Time for the Stars, Glory Road, Time Enough for Love, and The Number of the Beast dealt explicitly or implicitly with incest, sexual feelings and relations between adults, children, or both. The treatment of these themes include the romantic relationship and eventual marriage of two characters in The Door into Summer who met when one was a 30-year-old engineer and the other was an 11-year-old girl, and who eventually married when time-travel rendered the girl an