In his book Dark Skies, political scientist Daniel Deudney defends the thesis that human safety requires the preservation of ignorance.

Large-scale space expansion must be viewed as something akin to a full-scale nuclear war and assiduously avoided. . . . Learning to live on Earth in ways consistent with the continued viability of the biosphere clearly requires an acceptance of limits.

— Daniel Deudney

No human society has ever failed because it was too technologically advanced or possessed too much scientific knowledge. Many, however, have suffered catastrophe because of deficiencies in those areas. Even so, there has been no shortage of writers willing to defend the counterfactual thesis that human safety requires the preservation of ignorance. With his book, Dark Skies, Johns Hopkins professor Daniel Deudney provides a noteworthy addition to this clinically interesting genre.

Deudney’s book contains over 200,000 words, and costs only $36 retail, so purchasers will be rewarded with over 5,500 words for every dollar spent, which is well above industry standards for new hardcover books. The writing style is sort of Germanic, but it is better than Hegel, so readers who enjoyed The Phenomenology of Mind should find it at least equally pleasurable. It is true that most of the material is filler, but levity is provided by many original technical errors sprinkled generously throughout the text. Deudney claims, for example, that the temperature of objects in Earth orbit is 300 degrees Centigrade, that bodies made of water will freeze “instantly” in deep space, that the limit of Earth’s gravitational field is 30,000 kilometers, that objects in space “must move fast or they will fall down,” and — contradicting Newton and Copernicus, respectively — that different laws of motion apply to objects on Earth and in space, and that there is a geographical boundary between Earth and space. (N.b.: Earth is in space.) Crusaders for emergency measures to upgrade elementary- and secondary-school science education will doubtless find much useful evidence here to buttress the importance and urgency of their cause.

Deudney is not up to date on the latest progress in space science and technology, claiming, for example, that we now know that Earthlike planets are very rare in the universe. In fact, the results of the recently completed Kepler space telescope mission indicate that there are over 80 billion Earth-sized planets in the habitable zone of their stars in the Milky Way galaxy alone, with comparable results likely in trillions of other galaxies as well. He also appears unaware of the tour-de-force avalanche of technical advances demonstrated by the SpaceX company over the past decade. Indeed, he is not able to spell the name of the company correctly. But then again, who among us can?

The more serious problems with the book appear when we consider Deudney’s ideas. Deudney, a former senior researcher with the Worldwatch Institute, a Malthusian think tank, places no value on people. As he puts it, “exponential humanism, devoted to the perpetual expansion of human biomass, easily slides into planetary-scale ecocide.” In fact, he says, such additional human biomass in the form of new extraterrestrial branches of human civilization represents a threat, because it could unleash technological progress.

“If the monstrosities and menaces of the ever-widening technological cone of possibility can be thwarted only by staying within a narrow path of human preservation and enhancement, then space expansion must be assessed for its effects on the reversals, regulations, and relinquishments constituting the barriers of restraint. . . . If space expansion makes the creation and preservation of restraints even more difficult, the probability of otherwise unrelated catastrophic and existential outcomes will rise, making it a potent catalyst for multisided disaster.”

This is one of the major reasons why, according to Deudney, efforts to colonize Mars must be stopped before it is too late. “Once a viable human colony on Mars has been established,” he says, “a crucial threshold will have been passed and the path opened to the full range of catastrophic and existential threats likely to result from space expansion.”

Another reason is that once there are Martians, they, alongside other, allied extraterrestrials, would attack Earth. “If the expansion of space continues,” Deudney says, “the day will inevitably come when Terra is reduced to a marginal player, at the mercy of its gargantuan, and probably monstrous, off-spring.”

The key weapon that the Martians will use in destroying Earth is the diversion of asteroids to cause catastrophic impacts, a stratagem that Deudney says might also be used by a terrestrial superpower to crush the rest of the globe. For this reason, he warns, asteroid mining must be stopped. Why the Belters might want to use their settlements as kamikaze projectiles remains unexplained, as does why a nuclear power would use an easily divertible — it’s infinitely easier to make an asteroid miss a planet than hit one — method of attack (one, moreover, taking years to strike its target) and prefer it to much faster delivery using ballistic missiles, aircraft, or even ships.

To prevent such catastrophes, we need to make sure that launch costs remain high. “Everything that space expansionists want to do in space depends upon accessing space more cheaply,” says Deudney. “If technological breakthroughs make possible cost reductions of several orders of magnitude, reversals and relinquishment will become vastly harder to achieve and maintain.”

Technological and scientific progress have been the primary engines responsible for advancing the human condition since the Stone Age. Deudney, however, urges us to regard them with terror. We simply must stop them. So let’s cripple our space program.

Truly, fear is the mind killer.

This article was originally printed on National Review. Reused with permission of the author.