That is the most irrational statement I've ever heard. But I suppose the author _believes_ this statement to be true. There is so much in this world that each of us must personally determine what to believe... because there si so much of this world that we cannot personally touch, see and feel. The naturalist _believes_ that nothing exists besides what he can experience with his own physical senses. Yet someone else could _believe_ the obvious, that the metaphysical - like purpose, meaning, idea - even the concept of TRUTH itself - exists apart from the confirmational data of a microscope.