Good writers take the past and make it relatable. Great writers convey the present so that it remains eternal. Transcendent writers predict or control the future.
Thoreau inspired the theme of non-violent civil disobedience that would resonate throughout the 20th century, with his writings being collected and read by Gandhi, MLK, Mandela and more.
Tocqueville predicted war between Russia and America after both emerged as the great powers of the world -- centuries before it was to happen. He also warned about fundamental flaws in a democracy that plague America to this day.
Mill predicted the fundamental conflict between those who wanted expanded governance versus those who prided themselves on individual liberty -- the central debate in America and all other liberal democracies.
Simone de Beauvoir laid down the dynamics of gender roles and "masculinity by default" -- a state of affairs that continues to be examined and questioned.
Orwell and Camus critiqued Stalinism from a leftist perspective, a historical fact that stand the test of time -- and that while easy now, was the most difficult of choices then.
Ayn Rand looked past religion and all other forms of social coercion to establish a narrative around individuality that thrives to this day. You can love her or hate her -- but the fact is modern-day America is the strange intellectual offspring of her works and the Bible.
Harper Lee wrote tenderly and mournfully about the consequences of racism -- and offered a brief glimpse on how the future might be different, had we but tried to make it so.