The Dispossessed: An Ambiguous Utopia (Hainish Cycle, #1) by Ursula K. Le Guin

Centuries ago, the moon Anarres was settled by utopian anarchists who left the Earthlike planet Urras in search of a better world, a new beginning. Now a brilliant physicist, Shevek, determines to reunite the two civilizations that have been separated by hatred since long before he was born.

The Dispossessed is a penetrating examination of society and humanity – and one man’s brave undertaking to question the unquestionable and ignite the fires of change.