At the end of his stay at the Kreuzlingen clinic, which he entered because of his recurring nervous breakdowns, Aby Warburg decided to write a farewell speech addressed to the inmates themselves and to the clinic's doctors. Thus was born The Serpent Ritual, Warburg's form of catharsis, testament and "monstrous creature" that recounts his revealing encounter in 1895 with the Pueblo Indians. Fascinated by these men who he places "between the world of logic and magic", he describes his dance with live snakes, a magical ceremony that seeks to produce a real effect, rain. But the ritual of the serpent, an extreme form of the animist cult of the Indians, is the starting point of a reflection on the power of the image and symbols, necessarily linked to his conception of art. The serpent, present in the Bible, classical antiquity and medieval theology, is an "intercultural symbol that answers the question: what is the origin of elemental destruction, death and suffering in the world?", and it is for the Indians a living symbol. Warburg —explains Ulrich Raulff in a splendid epilogue— resorted to the snake, "symbol par excellence of the threat against human rationality, as an instrument to examine its ratio", and perhaps managed to "exorcise fear through symbols".