A strong refutation of the ontological argument is the
modal ontological argument's reverse, which challenges the premise that it is possible for a maximally great being to exist. By arguing that "it is possible that no maximally great being exists," it can be shown that if this is true, a maximally great being does not exist in the actual world. The ontological argument relies on the idea that existence is a perfection and that a maximally great being possesses all perfections, including necessary existence, but the reverse argument questions whether the very concept of a "maximally great being" is logically coherent and not simply a combination of undefined and impossible properties.