The wonders of science are so great that many philosophers and religious leaders predicted—with a sense of either hope or fear—that science would replace religion as the central organizing principle of our intellectual lives. Yet that hasn’t happened, despite the saturation of daily life with the fruits of science, from our tiny smartphones to the massive machines that power our globalized mass-market economy. When it comes to some of the most important ideological, political, and moral questions we face, the principles of scientific inquiry—including even basic statistical analysis and empirical observation—don’t always help us achieve consensus.