C.S. Lewis on a Strong Sense of “Unbelievable”Surprised by Joy: The Shape of My Early Life (Houghton Mifflin: 1995) p. 202.
If one kept (as rock-bottom reality) the universe of the senses, aided by instruments and co-ordinated so as to form “science,” then one would have to go much further — as many have since gone — and adopt a Behavioristic theory of logic, ethics, and aesthetics. But such a theory was, and is, unbelievable to me. I am using the word “unbelievable,” which many use to mean “improbable” or even “undesirable,” in a quite literal sense. I mean that the act of believing what the behaviorist believes is one that my mind simply will not perform. I cannot force my thought into that shape any more than I can scratch my ear with my big toe or pour wine out of a bottle into the cavity at the base of that same bottle. It is as final as a physical impossibility.