Did you read Cur Deus Homo? It moved me to read much of his work, including Proslogion. There's a large modern following, who discuss the latter pre-Thomistic 'proof' of a rationally compelling belief in God. Anselm even argues convincingly that it is not rational to refuse belief in "that than which nothing greater can be conceived", because this overarches and directs what is conceivable or rational.