What is the ontological argument and its features?

The Ontological Argument (OA) is related to the nature and essence of an object and this argument attempts to prove that God must exist by his very nature. Many philosophers formulate theories to support this view as they believed God can be defined into existence. Anselm did so by expressing God as ‘that than which nothing greater can be conceived’ and Malcom continues by describing God as a ‘necessary being’. Descartes believed that ‘God is a supremely perfect being whose existence is perfection’ and Plantinga continues to advocate this idea in ‘God is a maximally great being, in a possibility of different worlds’.  This argument takes shape as an a priori argument which is one based on a definition and the use of logic alone. This leaves the OA in a strong position as a priori arguments are more logically sound than a posteriori arguments as our experiences can be too subjective and misinterpreted. This is sustained as the OA is also an analytic argument which runs off the idea that sentences are true by definition of the term used to describe it.

OA presumes that existence is a predicate, a property or attribute, of God. According to Anselm, it is better to exist in reality than just in the mind. If God is that than which nothing greater can be conceived, he would not be such if he only existed in the imagination and must also exist in reality. Descartes similarly suggests that to be perfect, God must have necessary existence, otherwise one could imagine something more perfect which did actually exist. The OA is also a deductive argument which presents that if the premises of the argument, the supporting statements, are true, then the conclusion itself must be true. This offers us the chance to conclusively prove that God does in fact exist. God’s non-existence is a contradiction in terms, according to the OA. If one views God as a logically necessary being, as with the concept of numbers, it is always true even with the absence of experience to validate this truth.