This is a tale with many remarkable narrative incidents and characters, from Karl Barth to Carl Jung; one that is all the more powerful because of the interplay of worldly politics and spiritual crisis. The Great and Holy War presents a new theory of religious change.In religion, as in politics and culture, we should see the pace of change not as gradual evolution but as what biologists call punctuated equilibrium - long periods of relative stasis and stability, interrupted by rare but very fast moving moments of revolutionary or cataclysmic change, which then take decades or centuries for the mainstream to absorb fully. Like them or not, revolutions are the key to religious history.