Explain the Ontological argument
The ontological argument is an a priori argument: that is, it does not make any appeal to the facts of experience, but is solely concerned with the implications that stem from thinking about certain concepts. In this case, the concept under consideration is that of God. Two of the more enduring versions of the ontological argument are the versions posited by the 11th-century philosopher St Anselm and by the 17th-century philosopher René Descartes. Anselm began his argument by defining the concept of God as that "which nothing greater can be conceived of". Therefore, to think of God is to think of something "nothing greater than which can be conceived of". Anselm then proceeded to draw the implications that stem from this. The first point, he noted, is that something exists in our understanding when we think of it. Given that something exists-viz. God, or that "than which nothing greater can be conceived of"-it must be the case that God, being the greatest thing of which there can be a thought, must not just exist in our understanding but must exist in reality as well. Thus God exists. From a different perspective, Descartes advanced an argument that began with him defining God as a supremely perfect being. He then claimed that anything that is supremely perfect has existence. In this respect, a being that is completely perfect must, of necessity, possess all perfections. Thus, Descartes concluded, as God is the most perfect being, he must exist.
The ontological argument is an a priori argument: that is, it does not make any appeal to the facts of experience, but is solely concerned with the implications that stem from thinking about certain concepts. In this case, the concept under consideration is that of God. Two of the more enduring versions of the ontological argument are the versions posited by the 11th-century philosopher St Anselm and by the 17th-century philosopher René Descartes. Anselm began his argument by defining the concept of God as that "which nothing greater can be conceived of". Therefore, to think of God is to think of something "nothing greater than which can be conceived of". Anselm then proceeded to draw the implications that stem from this. The first point, he noted, is that something exists in our understanding when we think of it. Given that something exists-viz. God, or that "than which nothing greater can be conceived of"-it must be the case that God, being the greatest thing of which there can be a thought, must not just exist in our understanding but must exist in reality as well. Thus God exists. From a different perspective, Descartes advanced an argument that began with him defining God as a supremely perfect being. He then claimed that anything that is supremely perfect has existence. In this respect, a being that is completely perfect must, of necessity, possess all perfections. Thus, Descartes concluded, as God is the most perfect being, he must exist.