Many Protestants too, feel they can take a middle of the road approach in regards to the Pope. While they deny that his official teachings are infallible, and ignore papal directives to pray to Mary and the saints, and don’t believe in the Purgatory he preaches, they still revere him as a great Christian leader.
But if we take our lead from Lewis we see that the Pope doesn’t leave us with these sorts of options. He is either what he claims to be – the Church’s infallible guide – or he is a fool or, something worse. There isn’t any room for a middle ground.