Eventually, everything connects.
Charles Eames

Only a few material testimonies keep Aby Warburg‘s work and influence alive in the memory of his home town. In addition to the residential and the library building in Heilwigstraße, the only remaining evidence is an exhibition for the Hamburg Planetarium, Bildersammlung zur Geschichte von Sternglaube und Sternkunde (Image Collection on the History of Astrology and Astronomy), which was opened on April 15, 1930, shortly after his death. Stored from 1941 due to the war, temporarily reinstalled in 1945 and 1968, then lost until its rediscovery in 1987 and, after a short exhibition period, stored until today as the property of the University of Hamburg, we are dealing here with no less than a hidden treasure, the rediscovery of which is one of the most urgent and worthwhile cultural-political tasks of the Hanseatic city.

Warburg had conceived his »Cosmologikon« specifically for the former water tower, which at the end of the 1920s was to house the planetarium that had long been desired in Hamburg: »The water tower in the Stadtpark seems to me to possess a completely unknown and hitherto violently obscured luminosity« (letter to Felix von Eckardt, October 3, 1928). The striking rhetoric in his statements from this period, using metaphors from the semantic fields of sight and light, evokes the epistemological function that Warburg attributed to the combination of water tower, planetarium and picture collection. Built between 1913 and 1915 according to plans by the Dresden architect Oscar Menzel under the supervision of Fritz Schumacher, the water tower in Hamburg’s Stadtpark was closed down again in 1924. A new function therefore had to be found for the building, which was embedded in the educational program of the city park with its sculptures, sports and leisure facilities. With the Image Collection on the History of Astrology and Astronomy, an »didactic tool for the educated and uneducated« was to be created, »such as human European society has not yet possessed« (letter to the provincial school inspector Karl Umlauf, October 13, 1928).

Warburg and his assistants developed an exhibition that was to show in seventeen sections, primarily by means of photographic reproductions and plaster casts of various works of art »how mankind has tried to interpret and explain the stars and their mysterious movements to this day« (Gertrud Bing and Fritz Saxl: Die Bildersammlung zur Geschichte von Sternglaube und Sternkunde, in: Planetarium. Ein Führer, Hamburg 1930). The structure and sequence of the exhibition and the arrangement of the individual display walls were adapted by Warburg to the possibilities offered by the layout of the building: »In the booths, the reproductions would now have the task of illustrating the path from the pictorial-mythical to the symbolic-mathematical orientation in the universe through the various centuries and continents in terms of both developmental psychology and history« (letter to Karl Umlauf, October 13, 1928).

The cyclical nature of Warburg’s conception of cultural history, the idea that mankind has to go through this cycle from magic to enlightenment again and again in the course of its history, found its architectural expression in the layout of the Hamburg picture collection. Once visitors had viewed the individual exhibits in their historical sequence, they found themselves, at the end of the cycle, in front of the display wall dedicated to Johannes Kepler, a personality whose work was dealing with both astrology and astronomy. The exhibition therefore wanted to make it clear that even at a high level of scientific abstraction, the rational distance of the researcher to his subject could be threatened. Since the tension of polar opposites was also essential to Kepler's thinking (as it was for Warburg himself), the scholar became a »symbolic figure of those forces that create the space of thought« for the Hamburg art and cultural historian (Fritz Saxl: Warburgs Mnemosyne-Atlas, 1930). The structural layout and educational purpose of the picture collection were closely linked to this, with the visual presentation opening up a view of historical-philosophical reflection: the exhibition floor plan was also the floor plan of a cultural-scientific Gedankengebäude (building of thought). The necessity of the individual to free himself from this cycle through expertise and reflection found its metaphorical expression in the ascent to the adjoining library with books on astrological-historical topics, the instrument of independent enlightenment. In terms of the meaningfulness of its architectural structure, the exhibition was thus comparable to the Problemgebäude (building of problems) of the Kulturwissenschaftliche Bibliothek Warburg (Fritz Saxl: Die Kulturwissenschaftliche Bibliothek Warburg in Hamburg, 1930).

The afterlife of pre-existing motifs, the imagery of astrology, the cultural exchange between northern and southern Europe, the polarity of pictorial and abstract understanding of the world, in short, the entire basic circle of Warburg’s cultural scientific problems and the methodological principles of their solution were mapped on the basis of the exhibition. The presentation in the Hamburg Planetarium was characterized by its theoretical and educational focus, but also by the chosen institutional form as a partial sum of the scientific life’s work of its creator: the Image Collection on the History of Astrology and Astronomy was not only conceived as a permanent exhibition, it was also intended to serve as a veritable branch of the Kulturwissenschaftliche Bibliothek.

Warburg consequently regarded his picture collection as a »contribution to guiding the souls of young people, who should be introduced to a light-bringing exhibition, not a curious treasure house« (letter to Karl Umlauf, October 13, 1928). The light metaphor of this passage in the letter once again expresses – as in the phrase about the » violently obscured luminosity« of the water tower – the Enlightenment objective of the Image Collection on the History of Astrology and Astronomy, whose universal claim and didactic function can be summarized as an instrument of comprehensive popular education.


Uwe Fleckner is Professor of Art History at the University of Hamburg and at the China Academy of Art in Hangzhou and curator of the exhibition Image Collection on the History of Astrology and Astronomy taking place at the Planetarium Hamburg, 21.6. - 24.8.2025.