Contrast was – in Aristotelian terms – the Prime Mover of Huizinga's imagination. But its resolution, the quest for harmony, came a close second. Contrast generated tension and movement, harmony was balance and rest. Balance is perhaps the most important concept in Huizinga's entire methodological constitution. It was both prescriptive and descriptive, it applied to both scholarship and culture.

As a young linguist, he had opposed a one-sided, rational approach to language. As a historian, he argued against a one-sided emphasis on economic and quantitative history, and as a cultural critic he rejected a one-sided, materialistic development of culture. In Huizinga's world view, the creation of language was poetic impulse rather than pragmatic decision, historiography was a creative process, not a mode of bookkeeping, culture consisted of meaningful ritual, not soulless mechanisms. Throughout his life, Huizinga repudiated the separation of artistic and scientific powers. The historian's task, in his view, was, to combine ‘the greatest attainable objectivity’ with ‘strong subjective emotion’.

He sometimes described these two attitudes, objectivity and subjectivity, academic distance and passionate involvement, as classicism versus Romanticism. One represented rationalism, the other emotion. He used these two concepts to differentiate between ideal and dream, the beautiful whole and the suggestive detail. But he also said: ‘Those who go in search of the dreamland of Romantic moonshine are not infrequently the rigid rationalists of daylight.’ ‘Do not assume,’ he wrote in his ‘Brief colloquy on themes of Romanticism’, ‘that a certain rationalism, a certain sober realism, or even a certain classicism, excludes the Romantic attitude.’

Huizinga struggled with Romanticism, because both nationalism (to which he had an aversion) and history (which he loved), were its offspring. He therefore tried to distinguish the ‘bad’ from the ‘good’ Romanticism. He drew a line between pseudo-mysticism and the gentle art of lyricism; between nationalism and the rhetoric of blood and soil on the one hand, and the brotherhood of nations and supranational admiration on the other. There was the Romanticism that despised virtue and the one that venerated virtue, a Romanticism that could be seen as embracing play because it played the game of literature in all seriousness, and a Romanticism that murdered play, because it took literature too seriously.