Carl Gustav Carus, Pilgrim in a Rocky Valley (c. 1820) In this painting, the German physician, natural scientist, and art theorist Carl Gustav Carus (1789-1869) renders one of the central motifs of Romanticism – the religious person in an awe-inspiring natural landscape. Similar motifs also played an important role in the work of his friend Caspar David Friedrich. Carus's formal approach is typical of the Romantics (e.g., the center of the canvas is darker and the upper portions lighter). More than his landscape paintings, however, it was Carus’s theoretical work on Romanticism that assured him far-reaching influence.