The theme present in both texts is: People should not boast about themselves.
In "The Sun, Moon, and Stars," this theme may relate to the way humans have acted in relation to the gifts from the universe. Similarly, in "Arachne Spins Her Web," the story revolves around Arachne's pride in her weaving skills, which ultimately leads to her downfall. Both texts warn against the consequences of arrogance and boasting.