Full Idea
It is necessary that we should distinguish between ideas and the words by which things are signified. ...Images, words, and ideas are by many people altogether confounded.
Gist of Idea
We must be careful to keep words distinct from ideas and images
Source
Baruch de Spinoza (The Ethics [1675], II Pr 49)
Book Reference
Spinoza,Benedict de: 'Ethics', ed/tr. White,WH/Stirling,AH [Wordsworth 2001], p.89