By following the arguments between Coenraad J. Temminck and fellow ornithologists Louis J.-P. Vieillot and Nicholas Vigors, this paper sketches, to a degree, the state of zoological classification and nomenclature between 1825 and 1840 in Europe. The discussions revolved around the problems caused by an unstable nomenclature, the different definitions of genera and species and the best method to achieve a natural system of classification. As more and more naturalists concerned with classifying and arranging the groups of birds joined these (...) discussions, a broad platform for debate emerged around the 1840s that gave a major impulse to the disciplines of taxonomy and systematics. Natural history ceased to be dominated by a few influential scientific authorities and became the scientific field where debate preceded agreement and, with it, progress. With this ‘democratization’ of natural history, Temminck's status significantly changed between 1815 and 1840. After that year, his own views on classification along with certain economical and political developments in The Netherlands led Temminck to abandon the arena of ornithology and therefore, to lose his scientific authority. (shrink)