Full Idea
There is no reason to suppose - whatever Saint Anselm and Descartes may have thought - that mere existence is a valuable thing.
Gist of Idea
There is no reason to think that mere existence is a valuable thing
Source
Peter van Inwagen (Material Beings [1990], 12)
Book Reference
Inwagen,Peter van: 'Material Beings' [Cornell 1995], p.121
A Reaction
This is one of the simplest and most powerful objections to the Ontological Argument. God's existence may be of great value, but the existence of Hitler wasn't.