Here is the historian, investigating and judging what he has seen, heard, and read, and seeking out the true causes and consequences of the great deeds of the past. In his History, the war between the Greeks and Persians, the origins of their enmity, and all the more general features of the civilizations of the world of his day are seen as a unity and expressed as the vision of one man who as a child lived through the last of the great acts in this universal drama.