Over and over again he recalled her words: Suppose a vast number of civilizations are distributed throughout the universe, on the order of the number of detectable stars. Lots and lots of them. The mathematical structure of cosmic sociology is far clearer than that of human sociology.

The factors of chaos and randomness in the complex makeups of every civilized society in the universe get filtered out by the immense distance, so those civilizations can act as reference points that are relatively easy to manipulate mathematically.

First: Survival is the primary need of civilization. Second: Civilization continuously grows and expands, but the total matter in the universe remains constant.

One more thing: To derive a basic picture of cosmic sociology from these two axioms, you need two other important concepts: chains of suspicion and the technological explosion. I’m afraid there won’t be that opportunity.… Well, you might as well just forget I said anything. Either way, I’ve fulfilled my duty.

He had returned countless times to these words, analyzing each sentence from every angle and chewing over every word. The component words had been strung into a set of prayer beads, and like a pious monk he stroked them time and again; and unstrung them, scattered them, and restrung them in different orders until a layer of each had been worn away.

Try as he might, he couldn’t extract the clue from those words, the clue that made him the only person that Trisolaris wanted to destroy.

During his lengthy contemplation he strolled aimlessly. He walked along the desolate lakeside, walked through the wind as it grew ever colder, oftentimes completing a circuit of the lake unawares. Twice he even walked to the foot of the snow peak, where the patch of exposed rock that looked like a moonscape was blanketed with snow, becoming one with the snowcap ahead of him. Only then did his mood leave the track of his thoughts, Zhuang Yan’s eyes appearing before his own in the boundless blank white of the natural painting. But he was now able to keep his mood in check and continue turning himself into a thinking machine.

A month went by without him knowing it, and then winter came in full force. But he still conducted his lengthy thought process outside, sharpening his mind on the cold.

By this time, most of the prayer beads had been worn faint, except for twenty-one of them. These ones seemed only to get newer the more he polished them, and now emitted a faint light:

Survival is the primary need of civilization.

Civilization continuously grows and expands, but the total matter in the universe remains constant.

He fixated on these two sentences, the axioms Ye Wenjie had proposed for cosmic civilization. Although he did not know their ultimate secret, his long meditation told him that the answer lay within them.

But it was too simple a clue. What could he and the human race gain from two self-evident rules?