Final answer:
Peter Henry Emerson was urging photographers to capture the world as it is seen by a human eye, rather than focusing on technical aspects of the camera.
Step-by-step explanation:
Peter Henry Emerson argued that the camera should function as a human eye rather than a mechanical device. By making this argument, Emerson was urging photographers to capture the world as it is seen by a human eye, rather than focusing on technical aspects of the camera. He believed that the camera should be used as a tool to convey the human experience and emotions, rather than simply reproducing an objective image.