 in Art and Illusion (Wollheim 1963: 25). However, no general theory of depiction is presented in Art and Illusion, although Gombrich compares the perception of pictorial content with the phenomenon of aspect-switching or “seeing as”. He introduces “seeing as” with the ambiguous drawing of a duck or a rabbit that Wittgenstein’s Philosophical Investigations had made famous (Wittgenstein 1953: 194):