Full Idea
If I take God together with all his predicates (among which omnipotence belongs), and say 'God is', then I add no new predicate to the concept of God. ..A hundred actual thalers do not contain the least bit more than a hundred possible ones.
Clarification
A 'thaler' was a Prussian coin
Gist of Idea
You add nothing to the concept of God or coins if you say they exist
Source
Immanuel Kant (Critique of Pure Reason [1781], B627/A599)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.567
A Reaction
Norman Malcolm claims that 'necessary existence' adds something to a concept. We can compare a concept with and without contingent existence, but the comparison is void if the existence is necessary. I love Kant's objection, though.
Related Idea
Idea 4475 Saying a thing 'is' adds nothing to it - otherwise if my concept exists, it isn't the same as my concept [Kant]