The fundamental theme of hubris runs throughout the narrative, as the Númenóreans transition from a noble and blessed people to an empire consumed by pride. Their increasing resentment of their mortal nature and jealousy of the Elves' immortality leads them to challenge the very powers that blessed them, ultimately causing their destruction.

Tolkien explores the complex relationship between mortality and divine gift. The Númenóreans' inability to accept death as the natural fate of Men becomes their greatest weakness, leading them to pursue immortality through increasingly desperate and dark means, reflecting deeper philosophical questions about the meaning of life and death.

The gradual transformation of Númenor from a benevolent kingdom to a tyrannical empire demonstrates how power corrupts over generations. Through their increasing dominion over Middle-earth and their eventual fall to Sauron's influence, Tolkien illustrates how the desire for power can destroy even the most virtuous civilizations.