Full Idea
The fact that you can discuss the proposition 'God exists' is a proof that 'God', as used in that proposition, is a description and not a name. If 'God' were a name, no question as to its existence could arise.
Gist of Idea
You can discuss 'God exists', so 'God' is a description, not a name
Source
Bertrand Russell (The Philosophy of Logical Atomism [1918], §VI)
Book Reference
Russell,Bertrand: 'Russell's Logical Atomism', ed/tr. Pears,David [Fontana 1972], p.108
A Reaction
Presumably 'a being than which none greater can be conceived' (Anselm's definition) is self-evidently a description, and doesn't claim to be a name. Aquinas caps each argument with a triumphant naming of the being he has proved.