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How does Anselmās ontological argument attempt to prove Godās existence from the concept of a perfect being?
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Philosophy of religion
Detail of Religion, mural in lunette from the Family and Education series by Charles Sprague Pearce, 1897; in the Library of Congress, Thomas Jefferson Building, Washington, D.C.
St. Anselm of Canterbury formulated the ontological argument in his Proslogion (1077ā78) as an a priori proof for the existence of God.12
Anselm begins with the definition of God as "that than which nothing greater can be conceived" (aliquid quo nihil majus cogitari possit). His reasoning proceeds as follows:34
- Conceptual Existence: Even those who deny God's existence understand the concept of a being than which nothing greater can be conceived, meaning this being exists at least in the human intellect.4
- The Contradiction: Anselm argues that it is greater to exist in reality than to exist only in the mind. If the greatest conceivable being existed only in the intellect, one could conceive of an even greater beingāone that exists in both the intellect and reality.41
- Conclusion: To avoid this logical contradiction, the unsurpassably perfect being must necessarily exist in reality.13
While historically influential, the argument has faced significant criticism, most notably from Immanuel Kant, who argued that existence is not a predicate or property that can be added to a definition to prove reality.3