The tone of science fictionfilms is often a guide to the tone of the times the film was made: other worlds and species are viewed in turn as wonderful, terrifying, threatening, incomprehensible, and childishly benign.
... Pädagogik als System (1848)
Aesthetik des Hässlichen (1853)
Die Poesie and ihre Geschichte (1885)
Studien (1839-47)
Neue Studien (1875-78).
He published also ...