"Beyond the circle of the moon," Aristotle once observed, "there is no evil." It's one of those curious lines that reveal the divide between what we once were and what we now are—a divide marked by that almost over-famous "one small step" Neil Armstrong took on July 20, 1969, as he stepped out of the lunar landing module and walked upon the moon.
We could take Aristotle to be making simply an ethical point: Whatever harm a wild animal or an avalanche might cause, nature (physis in Greek, from which we get the English word physics) has no will to do wrong. Only humans possess the capacity for evil, and humans are confined to earth. The pale moon circles above us like a divine watchman. Or a prison guard.
More probably, Aristotle was observing something metaphysical. To an ancient observer, studying the scintillations in a night sky unspoiled by electrical lights, the heavens seem regular and mathematical. Beautiful and clean. Unchaotic. Beyond the circle of the moon is only order, where the formal stars bow to one another and dance in their quadrillions.
In either sense, Aristotle expresses something that seems outlandish to us, these days. "The past is a foreign country: they do things differently there," the novelist L.P. Hartley wrote. But when we think of outer space, the past is not just a foreign country. It's an alien planet. Modern people, C.S. Lewis suggested, look up at the night sky and imagine they are staring out into the void. The ancients and medievals thought they were looking not so much out as in: spectators in the great theater, watching a cosmic drama acted out before their eyes.
The change began in the Renaissance, of course, and built from Copernicus in the 16th century to Newton in the 17th. What shifted was, in essence, the place of the observer. After the great modern change, we think of the solar system by imagining that we stand outside it. We picture ourselves beyond even the orbit of the now-no-longer-planet Pluto. And standing at that imagined spot, we look back to see the entire solar system and think: Why, yes, there's the sun with the planets orbiting around it. Heliocentric, just as they said. From Galileo and Kepler on, we gradually learned to cast ourselves out into space. Long before the actual 1969 lunar flight, we had repositioned the human imagination to stand far past the circle of the moon.
So what did it really mean when Neil Armstrong and Buzz Aldrin walked on the moon that day, now 50 years ago? Well, first, there’s a reasonable argument that the moon landing presaged victory in the Cold War. The Russian launching of the Sputnik satellite in 1957 caused a panic in America, and for good reason: If communism could blast ahead of the Western democracies in futuristic science, then maybe the future really did belong to the Soviets. Twelve years later, the successful NASA mission demonstrated that the United States was far ahead of Russia. The result was both Reagan's confidence and the Soviets' fear that American science could build the Star Wars program. No moon landing, no fall of the Berlin Wall.
Equally, one could use the Apollo spaceflight as an image for what America can achieve when it has a clear goal, a horizon, for the nation. What are we for, and where are we going? Through the 1960s, the United States had an answer, and the country survived the turmoil of the decade in part because of that answer. We have a name for what America would be like if we somehow kept the 1960s sexual revolution but stripped away any sense of national purpose. We call it the 1970s. We call it disco.
Then, too, the space program appeared to sputter out that July day in 1969. Throughout the remaining Apollo flights, the space shuttle, and the space station, NASA seemed an agency uncertain of the reason for its existence. In the absence of a next clear goal, the national enthusiasm—every little boy with a model of the lunar module—faded with surprising speed. The probes sent beyond the solar system and the Mars rovers might have helped restore it a little, but the recent expansion of private industry into space is, in its way, clear testimony to NASA's failure. Without a goal, space exploration dies. What we had still unifying us in the 1960s, we lack today. Neil Armstrong's lunar stroll was 50 years ago, and no one has been back to the moon since the last Apollo flights.
One more effect of the moon landing seems worth mentioning, and that's what happened to science fiction: the literary change that the lunar mission gave us. Yes, there's an oddity here and an oddity there, but in truth the notion of the moon as a habitable place hardly ever appeared in literature before the Renaissance and the subsequent dawn of the modern age. And in most of the early modern works, the moon is mostly akin to a place in Utopia (1516) or Gulliver’s Travels (1726)—the setting of a satire, in other words, or an allegory for the human condition. Daniel Defoe's The Consolidator (1705) is a good example, using implausible space travel to mock Parliament. Francis Godwin's The Man in the Moone (1638) often appears on lists of the most influential science fiction, but its primary purpose wasn't to imagine lunar travel but to mock contemporary figures. Cyrano de Bergerac modeled his Voyage dans la Lune (1657) after Godwin's book, and, sure enough, the characters spend most of their time in thinly veiled social commentary.
By the mid-1800s, however, the modern sense of the moon had fully taken hold, and authors began turning out how-to-do-it novels, each with some theory about how the first true moon flight could happen. In 1865, Jules Verne produced From the Earth to the Moon. In 1901, H.G. Wells published The First Men in the Moon, drawing together several of the older themes—an alien-inhabited moon, an allegory of human society—with the imaginative technology of the emerging genre of science fiction.
By the mid-1900s, the eventual human arrival on an uninhabited moon was taken for granted, and the fiction moved to describing the society that would exist in that lunar-colonializing future. Robert Heinlein's The Moon Is a Harsh Mistress (1966) is among the best representatives of the class, along with Arthur C. Clarke's A Fall of Moondust (1961).
But after the 1969 moon landing, the expectation shifted again—to the notion that now we would see a rapid expansion of human settlement out into the solar system. The moon would be a pawn in interplanetary politics, a hostage in the fight between such dominant powers as Mars and the moons of Saturn. The moon would be the Atlanta airport of the solar system: the place where you change rockets and hurry to make your connection. Ben Bova's Moonrise (1996) and Ian McDonald's Luna: New Moon (2015) are both superior examples of science fiction in this niche.
That space mission 50 years ago—Neil Armstrong and Buzz Aldrin moonwalking on July 20, 1969—felt to science-fiction writers mostly a precursor, a first step, to the planets beyond. And set free by the American astronauts' actual arrival on the moon, they imagined the re-creation of human society in new and strange places. Of course, they all mostly saw that the people in those societies would remain human. And do human things. Beyond the circle of the moon, there is no evil—till human beings get there.