A major one which no one can overlook is technological and based on inventions and discoveries which have altered the whole basis of production and deeply affected social relations.
“This world, after all our science and sciences, is still a miracle; wonderful, inscrutable, magical and more, to whosoever will think of it.”
“African-Americans who might have disagreed with candidate Obama's left-of-center politics voted for him in 2008 because electing a candidate with brown skin was too historic an opportunity to miss.”