Oscar Gustave Rejlander (1813-1875) was a pioneer of English photography in the 19th century. His work is as innovative as it is diverse. It ranges from early experiments in photomontage and art photography to illustrations for Charles Darwin's last book "The Expression of the Emotions in Man and Animals." Through his multifaceted work, "Making Thoughts Visible" outlines a cultural history of Victorian photography in the mid-19th century, incorporating Rejlander's connections to the English royal family, his art and portrait photography, images of street children, and self-portraits in various roles. Oscar Gustave Rejlander is one of the most innovative photographers of the 19th century and, alongside Julia Margaret Cameron, Lady Hawarden, and Lewis Carroll, is among the most important photographers of the Victorian era. Bernd Stiegler is a professor of modern German literature in a media context at the University of Konstanz.