Another notable book by William James, The Varieties of Religious Experience, helped answer this question. The founder of pragmatism, the only distinctively American school of philosophy, James taught not only philosophy but, as Harvard professors did in those days, psychology and physiology as well.  He was a man of science but, for him, empiricism did not mean restricting our understanding to what science registers; he looked without prejudice at all kinds of human experience, of which religious experiences are among the most interesting. He talks about famous people such as George Fox as well as ordinary people who have received answers to prayer or psychic intuitions or visitations from recently-departed family members.

Many human beings have had moments of divine or non-natural awareness, probably more than feel comfortable talking about them publicly. Duke English professor Reynolds Price writes about his own battle with cancer.  During the course of his treatment, he had an encounter with Jesus in a vision or, as it seemed to him, in another dimension. After he published his story, he received letters from many people with similar experiences—experiences that they had never told anyone. My experience was not as out-of-line as I had thought.  

I decided to follow the voice and see where it would lead me.