He was willing to change his lifelong belief (or lack of belief) when it was contradicted by evidence, as he saw it.

He describes it rather differently: "This was not a case of defense and prosecution laying out evidence for my reason to pick through: I was altered down to the root of my being."

He later speaks of evidence, but what he takes as evidence is religious visions not further described. Whatever this experience was, on his own account no process of rationality played any role in his conversion.