“The class struggle, which is always present to a historian influenced by Marx, is a fight for the crude and material things without which no refined and spiritual things could exist. Nevertheless, it is not in the form of the spoils which fall to the victor that the latter make their presence felt in the class struggle. They manifest themselves in this struggle as courage, humor, cunning, and fortitude. They have retroactive force and will constantly call in question every victory, past and present, of the rulers. As flowers turn toward the sun, by dint of a secret heliotropism the past strives to turn toward that sun which is rising in the sky of history. A historical materialist must be aware of this most inconspicuous of all transformations.”