Nathaniel Southgate Shaler (1841-1906) was an American paleontologist and geologist who wrote extensively on the theological and scientific implications of the theory of evolution. Shaler studied at Harvard under the legendary Louis Agassiz and would go on to become a Harvard fixture in his own right, as lecturer and professor of paleontology for two decades (1869-1888) and as professor of geology for nearly two more (1888-1906).