Kepler’s 1604 Optics proposed among many other things a new way of locating the place of the image under reflection or refraction. He rejected the “perspectivist” method that had been used through antiquity and the Middle Ages, whereby the image was located on the perpendicular between the object and the mirror. Kepler faulted the method for requiring a metaphysical commitment to the action of final causes in optics: the notion that the image was at that place because it was best (...) or appropriate for it to be there, and for no other discernible reason. Kepler’s new theory relied on binocular vision and depth perception to determine the location of the image. No final causes were required, and he showed that the image would in general not be found on the cathetus. According to modern scholarship, Kepler’s theory was part of his revolutionary transformation of the science of optics, and his abandonment of perspectivist optics; as a consequence, the theory of binocular vision is also thought to be original with him. This article demonstrates that the very same theory of binocular image location was set out by Giovanni Battista Benedetti some twenty years earlier, and his writings on this subject may have been Kepler’s unacknowledged source for his own theory. Furthermore, another mathematician, Simon Stevin, developed much the same theory at the same time as Kepler and, it seems, independently of either Benedetti or Kepler. The discovery of these other binocular theories, especially Benedetti’s, requires us to recognize that Kepler’s revolution emerged out of a wider dissatisfaction with the foundations of perspectivist optics, which other lesser-known opticians resolved in much the same way that Kepler did. (shrink)

Images share a common feature with all phenomena of imagination, since they make us aware of what is not present or what is fictional and not existent at all. From this perspective, the philosophical approach of Kendall Lewis Walton—born in 1939 and active since the 1960s at the University of Michigan—is perhaps one of the most notable contributions to image theory. Walton is an authoritative figure within the tradition of analytical aesthetics. His contributions have had a considerable influence on a (...) broad range of topics, such as the role of categories in the understanding of the arts (Walton, “Categories of Art”. Philosophical Review, 79(3): 334–367, 1970), the ambiguous nature of emotions in the experience of fictional stories (Walton, “Fearing Fictions”. The Journal of Philosophy, 75(1): 5–25, 1978), the transparency of photographic images compared to other depictions (Walton, “Transparent Pictures: On the Nature of Photographic Realism”. Noûs, 18(1): 67–72, 1984) and, above all, the development of a general theory of fiction as imaginative activity. His 1990 book Mimesis as Make-believe: On the Foundations of the Representational Arts collects and re-elaborates articles Walton published on the subject since the 1970s. Though he does not attempt to give a definitive answer for what imagination is, Walton thoroughly investigates its role in all cases of representational works, describing depictions as a specific case of “make-believe” activity: images, in short, are specific props of a visual and perceptual “make-believe” game. (shrink)