Here is the infallible test. Imagine yourself in a situation where you are alone, wholly alone on earth, and you are offered one of the two, books or men. I often hear men prizing their solitude but that is only because there are still men somewhere on earth even though in the far distance. I knew nothing of books when I came forth from the womb of my mother, and I shall die without books, with another human hand in my own. I do, indeed, close my door at times and surrender myself to a book, but only because I can open the door again and see a human being looking at me.
Martin Buber