What is the theme of "If I Forget Thee, Oh Earth..." by Arthur C Clarke?
One of the central themes in Arthur C. Clarke's classic science fiction short story "If I Forget Thee, Oh Earth" is individualism. It is a post-apocalyptic tale told from the unusual perspective of those who have evaded the apocalypse because they're settled on the moon. The main character is a young boy named Marvin who is driven out onto the surface of the moon by his father, the head scientist of the Lunar colony, to witness the lifeless, irradiated earth.
Marvin's father explains that the Lunar colony represents the best, brightest and last of the human race, and that some day those who are a part of the colony will return to Earth and recolonize it. He emphasizes the hardiness and energy of the lunar colonists and their strong individualism.
Alas, at the end of the story Marvin realizes the goal to resettle the Earth is perhaps unattainable, and certainly impossible in his lifetime. He becomes aware he will spend the rest of his life on the Moon and may eventually take his son onto the surface and instill in him the hope of recolonizing Earth.
While there were many stories dealing with nuclear destruction and devastation in the era Clarke published this story (1951), few capture the sad wistfulness of global destruction quite like this one.
This is probably Clarke's most famous cautionary tale, which is a story with a warning about what will happen in the future if society continues along its present course. The science fiction genre often embraces this leit motif (recurrent theme), which is indeed one of its principal characteristics.
'Take care of the planet before it's too late' could be one theme, or perhaps 'The armaments race will ultimately lead to an atomic holocaust.' Another could state something like this: 'Mankind will not inherit a future world better than the one he bequeaths today.'