Book 1

This book re-examines Anselm's famous arguments for the existence of God in his Proslogion, and in his Reply. It demonstrates how he validly deduces from plausible premises that God so truly exists that He could not be thought not to exist. Most commentators, ancient and modern, wrongly located his argument in a passage which is not about God at all. It becomes evident that, consequently, much contemporary criticism is based on misreading and misunderstanding his text. It reconstructs his reasoning through three distinct but logically connected stages. It shows that, even if Anselm's crucial premises are sceptically interpreted, his conclusions still follow. Properly understood, this argument is not vulnerable to the standard criticisms, including Gaunilo's 'Lost island' counter-example.

Book 5

In this book, Richard Campbell reformulates Anselm's proof to show that factual evidence confirmed by modern cosmology validly implies that God exists. Anselm's proof, which was never the "ontological argument" attributed to him, emerges as engaging with current philosophical issues concerning existence and scientific explanation.



Because every observable thing has a beginning, it can be deduced that there is always in reality something than which a greater cannot be thought, which exists necessarily. It follows that its non-existence is inconceivable. Anselm then proves that this is the God in whom he believes, who alone so truly exists that He could not be thought not to exist. The contingent nature of the universe is therefore a consequence of the proven belief that God is the Creator of everything else.