How the world lost its centre: the relation of truths and facts in Middle Ages and early modernity.

Abstract

In the Middle Ages, it was commonly accepted that Jerusalem was the centre of the (inhabited) world. This was proven not just from Biblical sentences, but also from an alleged empirical fact: people claimed that in Jerusalem at noon during the summer solstice a vertical pole throws no shadow, the sun being in its zenith. This is not true and even it if were, it would not prove anything. This should have been easy to grasp for an educated medieval person; still, the claim was repeated over and over again. Only at the end of the fifteenth century, it suddenly became subject to investigation and criticism, whereupon it quickly became completely obsolete. The reasons for this shift are not completely clear, but the growing availability of information likely played a role. The episode demon- strates both the importance and the unimportance of em- pirical facts in the Middle Ages. Jerusalem's central position was not just the symbolic representation of a spiritual truth, it was considered empirically true as well; but this fact was not critically evaluated. The “truth” of Jerusalem's centrality dictated what “facts” were credible. The questioning of these presumed facts at the end of the fifteenth century should therefore be regarded as an important turning point in European intellectual history. After all, the realization that truths must be based on inde- pendent facts is a basic precondition of modern science.