In December 1905 the zoologist Karl Möbius, director of the Berlin Museum of Natural History, spoke on the leading ideas of his theory of the animals' aesthetical value to the members of the famous "Mittwochs-Gesellschaft". He wanted to demonstrate how the mysterious aesthetical effect of living creatures could be explained in an empirical way by biological and psychological facts. Möbius' "aesthetic of animals" is an important part of the antimetaphysical tradition of the German 19th century aesthetic of nature. Möbius continued the aesthetical work of the naturalists A. von Humboldt (1769-1859) and M.J. Schleiden (1804-1881). His empirically founded aesthetic is similar to that of the English philosopher and statesman E. Burke (1729-1797) and to that of the philosopher, physicist and psychologist G.T. Fechner (1801-1887).