Joseph Beuys is one of the most influential German artists of the 20th century, whose work transformed the whole German society regarding its understanding of the task of fine art. At the core of his philosophical system is social sculpture, which derives from an extended definition of the unity of art and society. According to Beuys, the man who has free will works on the autonomous development of the evolutionary process with the use of heat (love); Beuys started working with fat and felt to promote this heat process. His work Sealed Letter, the property of the Ludwig Museum, is characteristic of Beuys' broad spectrum of anthroposophical ideas. The responsible artist – Beuys says that anyone can be such an artist – becomes the guardian and the imparter of the archaic traditions, and his main task is to be cognizant of the mystery of world creation and to pass on this knowledge. The equation of "art = capital" defines the only possible path of human development.