Many think Covid-19 is some kind of alien invasion that spells the end of the world. But the real threat to us is a much deadlier virus: a hatred of all the values that have underpinned our civilization for centuries. For years, I was puzzled as to why the Roman Empire ceased to exist and was replaced by communities that were uncivilized by comparison. How and why could mankind’s progress reverse in this way? Recent experience has eliminated the mystery.