Huizinga was not a thinker. At least, that was his own view. ‘My mind did not incline in general towards problems of a theoretical nature,’ he wrote in his memoirs. Dabbling in theory was harmless, but he advised his students against delving too deep, since it would only distract them from the historian's real work. But on another occasion, he reflected that history without theory was inconceivable. The same man who wrote that ‘a teaspoonful of theory’ was enough also wrote a whole series of theoretical essays and treatises which together filled a small volume.

In those essays, Huizinga tried to capture what was by definition impossible to pin down, he sought words for the mercurial. Essentially, he kept saying the same thing in different words. And naturally, he took contrasts as his point of departure. ‘Again and again we are brought back to that series of oppositions between which historical thought moves. Does history set out to know the particular or the general, the concrete or the abstract, the unique occasion or the regularity of repetition? Is its knowledge that of vivid representation or is it conceptual? Is its methodological goal analysis or synthesis, is its object of study individuals or the masses, personal or collective influences?’ His answers to each of these questions, of course, was: both.

Historical consciousness had a natural tendency to focus on the specific and dramatic, the particular and unique. On the other hand, the unique could only be understood in relation to the universal. ‘For someone lacking a sense of history, the assassination of Floris v and that of the De Witt brothers remain completely equivalent miscellaneous pieces of information. The particular can only be approached through abstraction. The image and the concept are not diametrically opposed. Once this polarity of historical knowledge has been properly understood, answering certain questions that have vigorously divided opinion and triggered fierce debate becomes a simple matter. All those questions that appear to have only one of two answers (“what happened here, was it this or that?”) can actually be resolved in the same way: both, it was one within the other.’

Huizinga had ample reason to concern himself with theory.