There are many traps along the way of exploring Eye and Brain. It is important to avoid the temptation of thinking that eyes produce pictures in the brain which are perceptions of objects. The pictures-in-the-brain notion suggests an internal eye to see them. But this would need a further eye to see its picture-another picture, another eye-and so on forever, without getting anywhere. (Gregory, 1997, p.5).I wonder if this was in the first edition, back in 1966.
Gregory, R. (1997). Eye and Brain. 5th edition.