For much of the past century, theologians have busied themselves reconceiving the doctrine of the Trinity. Taking cues from Adolf von Harnack, some complain that the lively God of the Bible was domesticated by the fateful triumph of “classical theism,” which imprisoned the Triune God in the static, ahistorical, impersonal categories of Greek philosophy. Heidegger captured the mood: No one, he famously said, would want to pray, sacrifice, sing, or dance before Aristotle’s unmoved Mover.