The effects of technology on religious belief, and of religious belief on technology, are great but insufficiently explored. Often religious communities have been the inventors, the popularizers, or the preservers of technologies. One important example, which Lewis Mumford called to our attention long ago in his Technics and Civilization (1934), is the intimate relationship between medieval monastic life and the invention of reliable clocks. It was the need to be faithful in keeping the horæ canonicæ, the canonical hours of prayer, that stimulated the creation of accurate timepieces. But of course, this invention spread to the rest of society, and over the centuries has come to shape our experience of time...