max earnst - photomontage

During the 1920s, Max Ernst was involved in Dada & surrealism works. He invented the graphic art techniques of "frottage", which involves pencil rubbings being used as an image source and "grattage" which showcases image's imprints being revealed by scraping away paint.

He never received any formal art training, and studied psychiatry and philosophy at the university level. After serving in the first world war, he found Dada and fellow artists who worked in a manner similar to his. 
His own work, which reflected his university studies of art history and psychology, as well as his World War I battle experience, conjured up fantastical dream worlds with disparate parts. Calling himself "Dada Ernst"—a pun on the German meaning of his last name ("serious")—the artist believed that beneath its absurdity, Dada had an earnest point. 

The moral underpinning is suggested in a photomontage, in which Ernst collaged human arms atop the wings of an airplane, conflating the corporeal and industrial—a recurring Dada theme. In the lower corner, three civilians demonstrate how arm holds would be used to carry wounded soldiers, an unsettling reminder of the destructive capability of World War I's new technologies.