While Bastian considered himself to be extremely scientific, it is worth noting that he emerged from the naturalist tradition that was inspired by Johann Gottfried Herder and exemplified by figures such as Alexander von Humboldt. For him, empiricism meant a rejection of philosophy in favor of scrupulous observations. As a result, he was extremely hostile to Darwin's theory of evolution because the physical transformation of species had never been empirically observed, despite the fact that he posited a similar evolutionary development for human civilization. Additionally, he was much more concerned with documenting unusual civilizations before they vanished (presumably as a result of contact with Western civilization) than with the rigorous application of scientific observation. As a result, some have criticized his works for being disorganized collections of facts rather than coherently structured or carefully researched empirical studies.