W.H.R.Rivers

“ The generally received explanation of the illusion in Aristotle’s experiment is that two parts of the skin are being touched which in the ordinary position of the fingers have always been touched by two objects. If this is correct, we might expect to find that if two parts of the skin ordinarily touched by one object are simultaneously touched by two objects, there would be the illusive perception of one object, and such is the case. The illusion occurs most readily in a person unaware of the nature of the experiment. ”

“ Here, following an unusual position of the eyes, an object is seen double because it stimulates parts of the retinae ordinarily stimulated by two objects, and the modification has also its analogue in the visual sense. ”