A year before the British surrender at Yorktown, John Adams wrote to his wife Abigail: “I must study Politicks and War that my sons may have liberty to study Mathematicks and Philosophy.” It’s a simple point: times defined by the former are not times defined by the latter. C. Bradley Thompson understandably desires that Americans “rediscover the philosophy of Americanism,” the philosophy—at least as he understands it—of the American Founding. What Thompson misunderstands, though, is that ours are once again times of war and politics; no mere philosophy can save us now. Americans of the founders’ age could realize the...