Sam Harris on The ontological argument
Harris dismisses the ontological argument as a word game that has never persuaded anyone who did not already believe.
Harris has addressed the ontological argument briefly in various discussions and finds it transparently fallacious. The argument attempts to derive God's existence from the concept of a maximally great being — but no amount of conceptual analysis can establish the existence of anything in the real world. You cannot define something into existence, whether it is God, a perfect island, or a maximally great pizza.
He regards the ontological argument as a case study in the misuse of philosophical sophistication. The argument's logical structure appears rigorous, but it depends on premises — particularly that it is possible for a maximally great being to exist — that are doing all the work and cannot be established independently of the conclusion. The appearance of logical rigour conceals a question-begging assumption.
Harris has noted that the ontological argument is never the reason anyone believes in God. People believe because of upbringing, community, emotional experience, or existential need, and the ontological argument is encountered later as a philosophical curiosity. Its failure to persuade anyone who does not already believe is, in his view, telling evidence that something is wrong with it, even if one cannot immediately identify the logical error.
“The ontological argument is, at best, a parlour trick. It has never once caused a thoughtful person to believe in God who did not already believe.”