This book. The author compared the rich in the society at that time to the day race that would evolve, and the poor in the society at that time to the night race that would evolve. Through this story, it reflects the drawbacks and contradictions of the gap between the rich and the poor between the capitalists and the workers in his society. He is afraid that human beings will kill each other in the future society, which is similar to the tragic ending of "man cannibalism", which expresses his yearns for the beauty of a communist society and living an equal, Good vision.

As a member of mankind, and as the hope of the future development of society, I should study hard, enrich my brain, exercise my body, strengthen my limbs, love labor, purify the environment, and avoid becoming a person whose intelligence and physical strength are degraded and slaughtered like the race during the day.