III. A Robot Must Protect Its Own Existence, As Long As Such Protection Does Not Conflict with the First Law.

IV. A Robot May Do Anything It Likes, Except Where Such Action Would Violate the First, Second, or Third Laws.

THE SPACER-SETTLER STRUGGLE was at its beginning, and at its end, an ideological contest. Indeed, to take a page from primitive studies, it might more accurately be termed a theological battle, for both sides clung to their positions more out of faith, fear, and tradition rather than through any carefully reasoned marshaling of the facts.

Always, whether acknowledged or not, there was one issue at the center of every confrontation between the two sides: robots. One side regarded them as the ultimate good, while the other saw them as the ultimate evil.

Spacers were the descendants of men and women who had fled semi-mythical Earth, with their robots, when robots were banned there. Exiled from Earth, they traveled in crude starships on the first wave of colonization. With the aid of their robots, the Spacers terraformed fifty worlds and created a culture of great beauty and refinement, where all unpleasant tasks were left to the robots. Ultimately, virtually all work was left to the robots. Having colonized fifty planets, the Spacers called a halt, and set themselves no other task than enjoying the fruits of their robots’ labor.

The Settlers were the descendants of those who stayed behind on Earth. Their ancestors lived in great underground Cities, built to be safe from atomic attack. It is beyond doubt that this way of life induced a certain xenophobia into Settler culture. That xenophobia long survived the threat of atomic war, and came to be directed against the smug Spacers—and their robots.

It was fear that had caused Earth to cast out robots in the first place. Part of it was an irrational fear of metal monsters wandering the landscape. However, the people of Earth had more reasonable fears as well. They worried that robots would take jobs—and the means of making a living—from humans. Most seriously, they looked to what they saw as the indolence, the lethargy, and the decadence of Spacer society. The Settlers feared that robots would relieve humanity of its spirit, its will, its ambition, even as they relieved humanity of its burdens.