We also tend to simplify history; but the pattern within which events are ordered is not always identifiable in a single unequivocal fashion, and it may therefore happen that different historians understand and construe history in ways that are incompatible with one another. Nevertheless, perhaps for reasons that go back to our origins as social animals, the need to divide the field into 'we' and 'they' is so strong that this pattern, this bi-partition - friend-enemy - prevails over all others. Popular history, and also the history taught in schools, is influenced by this Manichean tendency which shuns half-tints and complexities: it is prone to reduce the river of human occurrences to conflicts, and the conflicts to duels - we and they, Athenians and Spartans, Romans and Carthaginians.

Primo Levi, The Drowned and the Saved