The essay analyses the aphorism J 528 in Lichtenberg's Sudelbüchern as a model study of elementary questions and interests of the enlightenment, and as an example of the author's specific way of thinking and writing focusing on three aspects: 1) epistemological: Lichtenberg's text deals with the relationship between reason and anthropological as well as social factors, offering a kind of genealogy of rational behavior; 2) methodological and poetological: The text is a paradigm of Lichtenberg's transferring scientific method to non-scientific subjects; 3) reception: Lichtenberg's poetics find their complement in a specific way of reading: The reader has to be as active as the writer and is invited to do similar scientific experiments as does the observer of the public place he reads about. In other notes in the Sudelbücher, Lichtenberg attends to problems of physiology and psychology of perception as, in the 20th century, they will be a main issue in the theory of Gestalt. As Lichtenberg's way of thinking and writing is a criticism of self imposed immaturity as well as of dogmatic rationalism, enlightenment itself is enlightened.
Lichtenberg; experiment; scientific method; poetics