To Sail Beyond the Sunset, published on Heinlein's eightieth birthday, proved to be his final novel. While some critics have seen the novel, along with his other late works, as an expression of solipsistic despair, it seems more a defiant affirmation of life in the face of debilitating illness and approaching death. Indeed the title and the epigraph are taken from Tennyson's poem "Ulysses," in which the hero refuses to rest after his long journeys and instead sets out once more:
Come, my friends
'Tis not too late to seek a newer
Push off, and sitting well in order
The sounding furrows; for my
To sail beyond the sunset, and the
Of all the western stars, until I
The heroine and narrator of her own story is Maureen Johnson, known to Heinlein's readers as the mother (and later lover) of his most famous character, Lazarus Long, hero of Time Enough for Love (1973). Maureen, who was rescued from death in the twentieth century and whisked to the forty-fourth century by Lazarus and his extended family in The Number of the Beast (1980), spends most of this novel in prison on a parallel earth, which allows her to tell us the story of her life. Maureen gets to do what Heinlein characters love most — talk.
Perhaps the central concern of Maureen's story is sex — a theme common to all of Heinlein's novels since Stranger in a Strange Land (1961), but increasingly important since I Will Fear No Evil (1970). More precisely, it is a celebration of sexuality and a scathing attack on prudishness, repression, and attempts to limit sexual expression to socially approved forms. In fact, at one point Maureen suggests that the only unnatural sexual practice is monogamy. Maureen is a devotee of sex — with a man, with a woman, alone, in couples, in groups, as often as possible. And when she is not having sex, she delights in talking about it. But while Maureen is in many ways attractive in her unabashed sexuality, the novel's treatment of sex is ultimately unsatisfying. Part of the problem lies in the book's length (over four hundred pages) and in the frequency of the sex scenes. While Heinlein is by no means pornographic and rarely even very explicit in his sexual descriptions, the coy sex scenes grow increasingly tedious.
A second and more serious difficulty is that Heinlein's ideas about sex are not complex enough to demand elaboration over several hundred pages. His ideas are in fact simple: Sex is good — perhaps the highest good. Anyone mature enough to have sex should be free to have sex with any consenting partners. The only rules of sexual morality inferable from the novel are the necessity for consent, the importance of good sexual hygiene, and the absolute need to make provision for any children.
(The entire section is 1198 words.)