Anselm of Canterbury, a medieval theologian and philosopher, presented his concept of God through a work known as the “Proslogion,” which famously contains the ontological argument for God’s existence. Anselm’s definition of God starts with the idea that God is “that than which nothing greater can be conceived.” This definition forms the basis of his argument that it is foolish to disbelieve in God’s existence.
Anselm’s exposition hinges upon the notion that even the skeptic, who in his own contemplations denies the existence of a deity, apprehends what is communicated to him, and that which he apprehends resides within his cognition. It follows irrefutably that the entity of which no grander can be conceived must not be confined to mere cognition. If such an entity were to dwell solely in the intellect, it could also be envisaged to subsist in actuality, which is superior.
Consequently, should the entity that transcends all others in conception subsist solely within the intellect, then the supreme entity envisioned is, paradoxically, one which a more supreme could be envisaged. Nevertheless, this is an incongruity. Therefore, it is undeniably established that there exists an entity surpassing all in conception, and this entity persists not only in cognition but also in reality.
Anselm considers the skepticism of God’s existence to be without merit, for such disbelief engenders a logical discord within his syllogism. The very essence of God as the paramount conceivable entity inherently necessitates God’s existence; to conceptualize God is to recognize that existence is intrinsic to God’s preeminence. To refute God’s existence would be to undermine the principle of the paramount conceivable entity, which would result in a contradiction since the principle itself mandates existence for the entity to be truly paramount.
Moreover, Anselm postulates that God’s existence is necessary rather than contingent. An entity that subsists necessarily is of a higher order than one that does not, because the latter would rely upon an extrinsic cause or condition for its being. Hence, for God to embody the paramount conceivable entity, God must exist with necessity, and it would be both illogical and imprudent to assert the contrary.