Both of Anselm’s arguments are aimed at the same thing-proving God’s existence using sheer rational concepts. However, they go about it in two different fashions, seeking to prove God’s existence from two vantage points. Argument one seeks to prove God’s existence based upon the concepts of a greatest possible being/greatest conceivable being and existence as an attribute of that being. It is greater to exist in reality rather than mere understanding and “this being possesses each attribute to the highest degree.” If it is greater to exist in reality and the being is the greatest conceivable being, it follows that the being exists. Argument two is different than argument one because it employs the concept of necessary existence. God’s existence is either impossible or necessary. The existence of the Perfect Being cannot be contingent. Because the idea of a Perfect Being existing is not nonsensical or self-contradictory, it must be necessary. Both arguments are deductively valid meaning that, if the premises are true, then the conclusion has to be true.
Anselm’s Two Ontological Arguments
|God is understood or defined as a being “than which nothing greater can be conceived.”||God is defined as a maximally great or Perfect Being.|
|A thing exists either in (a) the understanding only or (b) in both understanding & reality.||The existence of a Perfect Being is either impossible or necessary.|
|It is “greater” to exist in reality than to exist merely in the understanding.||The concept of a Perfect Being is not impossible, since it is neither non-sensical nor self-contradictory.|
|If God exists merely in the understanding, then God is not the greatest possible being, since a being that existed in reality would be greater than a being that existed only in the understanding.||Therefore (a) a Perfect Being is necessary.|
|But God is by definition the greatest possible being.||Therefore (b) a Perfect Being exists.|
|Therefore, God exists not merely in the understanding but in reality as well|