It still amazes me how Kierkegaard grasped and elucidated the issues of Modernism and post-Modernism 150 years before they happened.  Better, he saw the direction everything was going and correctly explained how it would develop.  Here is one of many examples of his assessment that seems as relevant now as it was 150 years ago from The Concept of Anxiety:

It is not my desire to use big words in speaking about the age as a whole, but he who has observed the present generation can hardly deny that the discrepancy in it and the reason for its anxiety and unrest is this, that in one direction truth increases in scope and in quantity, and partly also in abstract clarity, while in the opposite direction certainty constantly declines.”