Throughout Death’s End, Earth must frequently face the instability of humans’ place in the cosmos. The Trisolaran Doomsday Battle and the inevitability of a dark forest strike on the Sun show that humanity is weak and prone to harm. At the same time, human morality and idealism drive humanity not to concede or accept defeat. When Cheng Xin refuses to activate the location broadcast as Swordholder, she is holding on to the slim hope that a future miracle will save humanity: “Cheng Xin did not vacillate; she had already made up her mind. This wasn’t a decision born of thought, but buried deep in her genes. These genes could be traced to four billion years ago, when the decision was first made” (180). Cheng Xin’s choice acknowledges the fact that humanity’s arrival at this pivotal moment reflects their resilience in the face of fragility, continuously striving for progress in an increasingly dangers and volatile world, galaxy, and universe.

Eventually, both the humans on Earth and the humans who populate the galaxy after fleeing Earth on Gravity and Blue Space develop a new perspective. More aware of the cruelty and indifference of the universe to this one species, they start taking less confrontational approaches to protecting themselves—erring on the side of staying unnoticed rather than aggressively threatening others.