Full Idea
If meaning is a private mental picture, what does 'the cat is NOT on the mat' mean, and how does it differ from 'the dog is not on the mat?'.
Gist of Idea
If meaning is mental pictures, explain "the cat (or dog!) is NOT on the mat"
Source
E.J. Lowe (Locke on Human Understanding [1995], Ch.7)
Book Reference
Lowe,E.J.: 'Locke on Human Understanding' [Routledge 2004], p.168
A Reaction
Not insurmountable. We picture an empty mat, combined with a cat (or whatever) located somewhere else. A mental 'picture' of something shouldn't be contrued as a single image in a neat black frame.