There’s plenty of housework to be done here on Earth, and our commitment to it must be steadfast. But we’re the kind of species that needs a frontier — for fundamental biological reasons. Every time humanity stretches itself and turns a new corner, it receives a jolt of productive vitality that can carry it for centuries.

The frontier is always the border of something, virgin territory where we can build new worlds, remake ourselves; always there’s this obsession with remaking ourselves. So to dream of the frontier is also to desire immortality. But there is no such thing as new territory. There are always previous civilizations, societies, families, and cultures. So when we build new worlds, there will be violence.

If the new world exploration did not come to anything like its happy expected fulfillment even in North America, where the odds were more favorable, it was because the new colonizers and settlers brought so much of the Old World in their refined equipment and their brutal customs with them. The wonder is rather that the hopeful dream has remained alive for so long, for some of its original luminosity still dazzles and blinds the eyes of many of our contemporaries who continue to pursue the same archaic fantasies, planning further voyages through outer space. Contemporary 'space age' prophets, who proclaim space exploration as the endless frontier and astronauts as the coming pioneers, throw an unrealistic glamour over both the past, and even more, the future of such efforts.

The founders of a new colony, whatever Utopia of human virtue and happiness they might originally project, have invariably recognized it among their earliest practical necessities to allot a portion of the virgin soil as a cemetery, and another portion as the site of a prison.

An optimistic view of the future would indicate that before long, the clear necessity of expanding humanity's horizons would cause ... space settlements to be built. The construction would also serve as a great project that not only would be clearly of great benefit, but might induce human cooperation in something large enough to fire the heart and mind, and make people forget the petty quarrels that have engaged them for thousands of years in wars over insignificant scraps of earthly territory.

We are a people of the frontier, born to it, bred to it, looking always toward it. And when the frontiers of our own land are gone, when we have drawn them all into an ordered world, then we must seek other frontiers, the frontiers of the mind beyond which men have not gone, the frontiers that lie out beyond the stars, the frontiers that lie within our own selves, that hold us back from what we would do, what we would achieve.

We take off into the cosmos, ready for anything: for solitude, for hardship, for exhaustion, death. Modesty forbids us to say so, but there are times when we think pretty well of ourselves. And yet, if we examine it more closely, our enthusiasm turns out to be all a sham. We don't want to conquer the cosmos, we simply want to extend the boundaries of Earth to the frontiers of the cosmos. For us, such and such a planet is as arid as the Sahara, another as frozen as the North Pole, yet another as lush as the Amazon basin. We are humanitarian and chivalrous; we don't want to enslave other races, we simply want to bequeath them our values and take over their heritage in exchange. We think of ourselves as the Knights of the Holy Contact. This is another lie. We are only seeking Man. We have no need of other worlds. A single world, our own, suffices us; but we can't accept it for what it is. We are searching for an ideal image of our own world: we go in quest of a planet, a civilization superior to our own but developed on the basis of a prototype of our primeval past. At the same time, there is something inside us which we don't like to face up to, from which we try to protect ourselves, but which nevertheless remains, since we don't leave Earth in a state of primal innocence. We arrive here as we are in reality, and when the page is turned and that reality is revealed to us - that part of our reality which we would prefer to pass over in silence - then we don't like it anymore.

You get to thinking of the Earth as an organism, a living thing. You get to worry about it, care for it, wish it well. National boundaries are as invisible as meridians of longitude, or the Tropics of Cancer and Capricorn. The boundaries are arbitrary. The planet is real. Spaceflight, therefore, is subversive. If they are fortunate enough to find themselves in Earth orbit, most people, after a little meditation, have similar thoughts. The nations that had instituted spaceflight had done so largely for nationalistic reasons; it was a small irony that almost everyone who entered space received a startling glimpse of a transnational perspective, of the Earth as one world.

Thought creates frontiers everywhere. That's all it can do. ...it is thought that has created the world; and you draw lines on this planet, "This is my country, that is your country". So how can there be unity between two countries? The very thing that is creating the frontiers and differences cannot be the means to bridge the different viewpoints. It is an exercise in futility.

I wanted to create an interesting scifi universe that didn't violate the laws of physics, and that means that you're limited to staying inside the solar system. I also wanted to get away from the ship-centric style of science fiction. Star Trek is ship-centric and it's all about the Enterprise — there are many other examples. What if we decided to get away from the obsession with ships and instead thought about big machines and structures that might be used to create a civilization inside the solar system?

The universe is all extremes. Monstrous gravity fields, or next-to-nothing ones; extreme cold, or heat so intense that solids and liquids cannot exist; multimillion atmosphere pressures, or near-vacuum.
Ice or fire. Niflheim or Muspelheim: the ancient alternatives, imagined by humans long before the Expansion.
It’s planets that are the oddities; the strange neutral zone between suns and space, the thin interface where moderate temperatures and pressures and gravity fields can exist. And if planets are anomalies, then planets able to support life are rarer yet—a zero-measure subset in that set of strangeness.
And within that alien totality, where do humans fit?

I have not met a speculative utopia I would want to live in. I’d be bored in utopia. Dystopias, their dark opposites, are a lot more entertaining.

We came into a homeless frontier, a place where we were not welcome, where nothing that lived was welcome, where thought and logic were abhorrent and we were frightened, but we went into this place because the universe lay before us, and if we were to know ourselves, we must know the universe...

As with science and technology, there could be a dark side of globalization, in which progress for some means poverty for others, as jobs and opportunities ebb and flow, securities and currencies fluctuate in value, and the tension between private profit and public good persists. But surely these are risks that we can manage in a world with an America more attuned to its larger purpose and responsibilities.
The final frontier is perhaps the most difficult, but it's also the most important — and that's the frontier of the human spirit. For too long, people have allowed differences on the surface — differences of color, ethnicity, and gender — to tear apart the common bonds they share. And the human spirit suffers as a result. Imagine a world in which we saw beyond the lines that divide us, and celebrated our differences, instead of hiding from them. Imagine a world in which we finally recognized that, fundamentally, we are all the same. And imagine if we allowed that new understanding to build relations between people and between nations. Our goal for the next twenty years should be to finally recognize that our differences are our greatest strength. That's true not only here in America, but in all parts of the world, where we've allowed historic rifts to poison the well of opportunity. They've arisen from the natural prides and passion of humanity. Only when we recognize that — when we respect the human spirit — will we be a great nation and a great world. These are the steps we must take in the next twenty years, as we reach out for the newest frontiers.