William Shakespeare (1564–1616) was a remarkable man. Combing through his work, one can find almost every conceivable bit of wisdom, good idea, or point of view. But until stumbling across the quote in Box 1, I hadn’t realized that Shakespeare, at the turn of the seventeenth century, in addition to being a poet and playwright, was also a modern geologist. Though without a university education, he somehow understood a key aspect of geology. Those lines in Henry IV were spoken as a geological metaphor for the winds of political change. But metaphors develop from widely understood notions. Despite Shakespeare’s clear priority by more than a century, historians of science stubbornly credit the founding of modern geology to James Hutton (1726–1797) and the new baby— Charles Lyell (1797–1875), born in the year of Hutton’s death, to whom the geological baton was transferred. The major conceptual insight that accounted at a single stroke for much that was observed in geology is the idea known as uniformitarianism (Fig. 1), though the term itself was not coined until 1840, by William Whewell. The idea of uniformitarianism, that the basic processes of Nature were the same in the past as they are today, was largely motivated by the observation that geological changes generally are very slow, a corollary that became known as gradualism. Its importance was that after long periods of time these slow, continually acting processes can accumulate large change. As far as proper priority goes, Hutton, like all educated people, must have read Shakespeare, so it might make a juicy, if typically fictional tabloid story to accuse him of cribbing his ideas from the Bard. In any case, the way ideas are sometimes just ‘‘in the air’’ and picked up independently by creative contemporaries is illustrated by the story of a young American named James D. Dana (Fig. 2). Dana was America’s leading geologist of the nineteenth century. In 1838, just two years after Darwin’s Beagle voyage had returned to England, Dana set forth on a voyage of global exploration designed to put an American foot in the door of what had been European domination of maritime exploration, the grand tradition that included James Cook (1729– 1778), Darwin, and many others. The objectives of the U.S. Exploring Expedition of 1838–1842 were to determine whether there was an Antarctic continent and to chart the volcanic island chains in the Pacific that had proven so dangerous to American whalers and traders. Lyell had speculated about the process that formed the many Pacific arcs of islands ringed by coral atolls, with active volcanoes at one end and no island inside the atoll at the other end. Essentially, Lyell thought that rising and subsiding volcanoes of different ages were responsible. Dana developed an almost opposite, but still gradualistic hypothesis, according to which the islands were built serially along the chain by undersea volcanoes, the cones of which eventually emerged from the surface and were colonized around their edges by coral. Dana noted the linear change in age of several Pacific island chains and, in 1873, published his idea that the first island was oldest, that it had been raised and then eroded back beneath the sea, while later islands in the chain were younger or just building, as spots on the ocean floor move over a volcanic source, forming a kind of geosyncline (Fig. 2). Many of Darwin’s earliest publications were on geology, and he had addressed this problem independently, earlier than Box 1: William Shakespeare, Geologist