Afterimages and Sensation

According to purists, visual experience can be exhaustively characterised in terms of a subject’s apparent perspective on external, public reality. Visual experience presents us (or if we are subject to illusion, apparently presents us) with aspects of the world beyond us—nothing more, nothing less. According to sensationalists, we cannot adequately characterise experience solely in terms of a subject’s apparent perspective on external, public reality. In addition, or instead, we must appeal to visual sensation, in some sense of that vexed term. 2 Afterimages have long formed a core part of the sensationalist’s critique of purism. Afterimages, so the argument goes, are manifestly different in character to ordinary perceptual experiences of the publicly visible world. As a result, they cannot be accounted for solely in terms of the ways in which apparent aspects of that world are presented to us. Instead, they must be characterised in terms of visual sensation. Critics of visual sensation have failed to provide an adequate response to the objection from afterimages. Even Ryle, who famously declares visual sensation to be a myth—the product of misguided philosophicalcum-psychological theories which ‘trade on, and pervert’ our ordinary understanding of sensation as bodily feeling (1949: 243)—confesses to a