In the beginning was the thing, and the thing was against God. So might begin the gospel of American secularism. The sudden flourish of secularism at the time of the United States’ foundation is incongruous, a rogue wave of rationality in a centuries-long sea of Protestant evangelising, sectarianism and God-talk. But it is undeniable. In 1788, with the adoption of its Constitution, the United States became the first modern republic founded on a legal separation of church and state. In a country that holds sacred the intentions of its revolutionary-era founders, those founders’ secular ambitions are clear.