ABSTRACT
In the Ontological argument, one begins simply with a concept of God. Of the three major arguments for the existence of God—the Cosmological, Teleological, and Ontological—only the last is entirely a priori. It is perhaps best to think of the Ontological argument as a family of arguments, each member of which begins with a concept of God, and by appealing only to a priori principles, endeavors to establish that God actually exists. Within this family of arguments the most important historically is the argument set forth by Anselm in the second chapter of his Proslogium. By far the most famous objection to the Ontological argument was set forth by Immanuel Kant in the eighteenth century. An objection against the Ontological argument calls into question the premise that God might have existed in reality.
