Full Idea
It is essential to distinguish images from exact ideas which are composed of definitions.
Gist of Idea
We must distinguish images from exact defined ideas
Source
Gottfried Leibniz (New Essays on Human Understanding [1704], 2.09)
Book Reference
Leibniz,Gottfried: 'New Essays on Human Understanding', ed/tr. Remnant/Bennett [CUP 1996], p.137
A Reaction
See Idea 12615, which is attacking Descartes and Locke, I think, but fails to register that Spinoza and Leibniz had got the notion of an 'idea' much more clearly.
Related Idea
Idea 12615 Mental representations are the old 'Ideas', but without images [Fodor]