Sir James Frazer's dense 12-volume masterpiece, The Golden Bough, still forms a cornerstone of social anthropology. Starting from a grove sacred to Diana, south of Rome, the good professor's lifetime study led him to conclude that our ancestors believed in magic as a means of controlling or mitigating elemental forces. These systems of faith began, at least in part, with a reverance for trees. This, in turn, led to religious beliefs in which tribal gods and spirits were propiated by shamans attuned to the emotional needs and fears of their people. To Frazer, the logical third stage in this process was scientific thought. As Robert Temple explains in his Illustrated Golden Bough (an attractive modern abridgement to the original) Frazer's "work made clear for the first time (around 1900) that matters of human belief are important, not so much for their content, as for their psychological significance."