[The] frontier metaphor has been basic to Heinlein's writing. Only eight of his … novels take place primarily on Earth, and four of them concern relations between humans and intelligent extraterrestrial beings, while a fifth concludes on the Moon. This outward spatial movement, coupled with a forward temporal movement, places Heinlein's characters in situations of extremity, facing the unknown and having to learn to understand it, in order just to survive. Whether they are in spaceships or on alien worlds, exploring or settling or righting wrongs—fighting off other species or learning to live with them, their situations parallel those of the American pioneers, for all that they are equipped with advanced technology, "scientific" thinking, and the benefits of historical hindsight. Even in a utopian situation, even in the present or near future here on Earth, even where mental or "psi" powers are involved, a kind of frontier ethic is invoked in order to make possible a free exercise of individual initiative, or to justify pragmatically certain measures that in more structured situations, such as those of the society we actually live in, would have to be considered extreme. On the frontier, Heinlein's heroes can be free from anything that technology and good will can overcome, such as physical slavery, mental bondage, the "prisons" of a single planet and the human body, the limitations of distance and even of death. They can be free to roam, explore, discover, earn fame and success, learn things that are useful for the individual or the race, or to achieve self-actualization.
That these freedoms are primarily available to those who can best profit by them—i.e., that they represent what [Alexei] Panshin calls a "wolfish" sort of freedom for "the Heinlein individual"—should not be too surprising, since this is a logical extension of the adolescent dream, especially its American versions. American literature and history are full of famous "wolfish" individuals who pioneered land, technology, and money matters in a society which encouraged everyone to seek, and enabled a few to achieve, their wildest dreams, believing the losses they brought to some were outweighed by the benefits they brought to all. That Heinlein is from a generation and a region which valued those achievements more than many people do today who take them for granted is surely relevant, but so is the fact that in any situation, certain people are more likely to succeed than others. In changing situations, such as the last five centuries of Western Civilization and the various futures Heinlein extrapolates from them, those who succeed are likely to be adaptable, even opportunistic. And Heinlein does not treat freedom, for the most part, as a simple escape. To be sure, some of his works contain large amounts of good-vs.-evil melodrama and lengthy sermons generalizing from inadequate particulars, while most of his work is pitched to the level of a reader of modest intellectual acheivement. More often than not, however, the melodrama is subsidiary, the sermons are in character, and freedom is a complex issue, involving both power and responsibility and requiring various kinds of trade-offs.
