The rustle of a leaf, the odor of a plant, the texture of bark or soil may be the minimal ingredients of animal and human cognition and evaluation. In this sense we can speak of the image as a signal of human import. The next step is the critical one, namely, the distinction between the signal and its referent. Is the rustle in the wood really dangerous or only an image of danger that may or may not turn into hostile teeth and claws? Once this question is raised—implicitly or explicitly—the possibility of cognition is born. The relations of signals, symbols, and signs to their referent and their separability from them are the subject matters of thinking and judging.Hence, imagination refers not only to sensing of images but also to the construction of images that may truly or falsely claim to be images of actuality. From the beginning, it would seem, sensory stimuli were utilized by the organism as signals of danger or satisfaction, but we do not know how many centuries elapsed before the appearances of things, events, and persons were perceived as clues to their human import—that is, when they became expressive of human concerns and when human beings created appearances to express these concerns.