A giant of nineteenth-century natural history study, Louis Agassiz made major contributions to modern knowledge of geology, paleontology, and zoology. Agassiz's fame in America was largely as a popularizer of natural history and teacher of advanced students. Founding the Museum of Comparative Zoology at Harvard was his lasting teaching and research achievement, and the Smithsonian Institution and National Academy of Sciences benefited from his impulse to professionalize science. A life-long opponent of the theory of evolution. Agassiz affirmed the magnificence of God's plan to all who would "study nature, not books".