Recall, The Fairy-Faith in Celtic Countries was published in 1911. Freud had published The Interpretation of Dreams in 1900, putting the unconscious on the map. Hypnosis was being widely used at the time in the treatment of mental disorders. The Society for Psychical Research, devoted to the scientific investigation of psychical phenomena, like telepathy, mediumship, and near death experiences, had been established in 1882. The Fox sisters kicked off the spiritualism movement in 1848, which attracted a lot of scientific attention through the rest of the 1800s and into the 1900s. The Fairy-Faith in Celtic Countries sits within this scientific (and pseudoscientific) stream, connecting the Celtic experience of fairies with psychical phenomena, the unconscious, trance states, dreams, hypnosis, altered states of consciousness, near death experiences, and telepathy. Celtic claims about the "second sight" fit naturally into this mix of perspectives about the mind and how it was making contact with unseen phenomena. The very first conclusion Evans-Wentz draws at the end of The Fairy-Faith in the Celtic Countries is this:
Fairyland exists as a supernormal state of consciousness into which men and women may enter temporarily in dreams, trances, or in various ecstatic conditions; or for an indefinite period at death.
His second conclusion is this:
Fairies exist, because in all essentials they appear to be the same as the intelligent forces now recognized by psychical researchers, be they thus collective units of consciousness like what William James has called 'soul-stuff', or more individual units, like veridical apparitions.
William James, the famous American psychologist and philosopher, had co-founded the American Society for Psychical Research in 1885. James was a skeptic about a lot of psychical phenomena, but he was an open-minded skeptic. For example, he attended seances to observe mediums communicating with the dead. James described his stance as "radical empiricism," arguing that the odd, kooky, spooky, and unusual should also command scientific attention. James argued that empiricism had become too wedded to scientific materialism and therefore ruled out, a priori, non-empirical, psychical, and spiritual phenomena on the front end. A truly radical empiricism, according to James, rejects the metaphysical prejudice at the heart of positivistic/scientistic accounts of empiricism.
Regarding the "soul-stuff" to which Evans-Wentz refers, in Principles of Psychology James attempts to describe how thoughts can be identified with neurological brain states. James is unwilling, commendably so, to reduce or identify subjective consciousness with neurological functioning. Clearly, James asserts, there is something "more" than neurobiology going on with consciousness. Some "soul stuff" seems to be in play. And yet, James admits, to speculate upon this "soul stuff" is jump into metaphysics, which goes beyond the bounds of empirical psychology. Still, ever curious and always daring, James floats a speculation. Instead of individual souls possessed by each person, James brings up the Greek belief in the animia mundi, a "world soul" that permeates the cosmos. This "soul-stuff" or "soul-substance" of the "world soul" is what Evans-Wentz refers to about the reality of fairies. Simply put, there is some psychical, soulish "stuff" at work in the world that humans, in certain psychological states, can "see" or "experience." The Celts, in their culture, whenever they saw or experienced this soulish, spiritual stuff, described it as "fairies." Thus, concludes Evans-Wentz, "Fairyland exists as a supernormal state of consciousness into which men and women may enter temporarily in dreams, trances, or in various ecstatic conditions." That these altered states of consciousness--experiences of Fairyland--were real is because "they appear to be the same as the intelligent forces now recognized by psychical researchers...what William James has called 'soul-stuff'."
Now, how has Evans-Wentz's argument held up over time? In some ways, not very well. The science Evans-Wentz deployed in The Fairy-Faith in the Celtic Countries has largely evaporated. The Fox sisters were frauds. Mediumship was debunked. Psychical phenomena hasn't been able to establish an empirical track record. Freud's influence on psychological research is practically nonexistent.
And yet, Evans-Wentz's theory opens up pathways to plausibility. Evans-Wentz's argument isn't that fairies as "tiny magical creatures with wings" exist. Rather, "fairies" were how the Celts described their encounters with the spiritual realm. Which brings us back David Bentley Hart's point about how enchantment is a saner and more rational posture toward the world given how it straightforwardly admits what we all know to be true, that existence is inherently mysterious. The exact same mystery William James struggled with when he tried to explain human consciousness and was thrust, as a consequence, into metaphysical speculation. If you're a radical empiricist you know these mysteries exist. They are staring right at you. Mysteries which necessarily point you toward metaphysics.
Radical empiricism demands that we honestly face and admit the mystery. The experience of this mystery was described by the Celts, given their culture, as Fairyland. The Otherworld. And in that sense, to be empirical is to believe in fairies.
