The modern Western world is in many ways a sustained attempt to deal with the unintended and unwanted problems related to the disruptive fracturing of Christianity in the 16th and 17th centuries; We can't understand ourselves or our world in 2017 - or its increasingly obvious and grave problems, and just how deeply rooted they are - unless we understand how much they owe to attempts to deal with the problems derived from what started 500 years ago, in 1517.