ABSTRACT As the wife and field assistant of geologist Walter Alvarez for the past 56 years, I have shared in adventures on five different continents. The quest to explore the history of our planet has given us insight and understanding of human history and culture as well. From the semi-arid Guajira desert of Colombia to the network of bike paths in Holland, to witnessing the September 1969 Revolution in Libya, from living in a medieval Italian hill town, visiting the Silk Road cities in Soviet Central Asia, participating in the plate tectonic revolution, helping found the Geological Observatory of Coldigioco, and continuing in the stimulating environment of the University of California, Berkeley, our lives have been rich in experiences. Linking it all together reminds us of the nearly infinite number of contingencies and decisions that shape each of our lives and contribute to our shared human history.

James Hutton’s Theory of the Earth , first published in 1785, was considered completely new by his contemporaries, different from anything that preceded it, and widely discussed both in Hutton’s own country and abroad—from St. Petersburg through Europe to New York. Yet a recent trend among some historians of geology is to characterize Hutton’s work as already behind the times in the late eighteenth century and remembered only because some later geologists found it convenient to represent it as a precursor of the prevailing opinions of the day. Painstakingly researched, richly referenced, and full of interesting stories, this Memoir shatters that line of thinking and restores Hutton’s standing as the father of modern geology, his ideas fully relevant to the geological problems of his day.