Uniformitarianism and Unity

William Bowie settled on a theoretical position that accounted for isostasy and the jigsaw-puzzle fit of the continents but ignored the facts of historical geology. And yet, as we have seen, he interacted and corresponded with historical geologists, particularly with Charles Schuchert (1858–1942). Of all the American geologists who ultimately rejected the theory of drift, Schuchert was perhaps the one who engaged the problem the most seriously. As America’s foremost historical geologist, Schuchert was well placed to argue the case for or against drift, and he grappled with the question of continental connections for at least fifteen years. In the end, however, Schuchert, like Bowie, rejected continental drift. Just as Bowie argued against drift because of beliefs grounded in the exigencies of geodetic practice, Schuchert ultimately argued against drift because of beliefs grounded in the exigencies of geological practice. For Bowie, the practice was Pratt isostasy, for Schuchert, it was Uniformitarianism. Charles Schuchert rejected continental drift because he interpreted it to be incompatible with Uniformitarianism. However, he did not reject it because he could not see drift taking place, as might be supposed. Uniformitarianism has meant many things to many people, and to Charles Schuchert in the late 1920s, it meant—rightly or wrongly—an essentially steady-state earth, whose details were forever changing but whose large-scale patterns and relationships remained the same. And this seemed to him to deny the possibility of major changes in the configuration of the continents. Moreover—and perhaps more importantly—for Schuchert, as for most historical geologists, Uniformitarianism was a form of scientific practice, a means of doing historical geology. It was, in fact, the primary means of doing historical geology. For Schuchert, abandoning Uniformitarianism was nearly tantamount to abandoning historical geology altogether. Not surprisingly, he declined to do this. Like William Bowie, Charles Schuchert settled on a theoretical position that preserved his scientific practice. But whereas Bowie’s theoretical ideas had little staying power, the alternative that Schuchert embraced influenced a generation of geologists to believe that drift was not so much impossible as unnecessary.