First let’s define terms. Naturalism excludes any reference to the supernatural as false or unknowable and so not worthy of serious consideration. Any evidence of the supernatural is dismissed as potentially explainable in naturalistic terms even if not explainable now. Fox TV's Gregory House is an exemplar of naturalism in this sense.
In contrast, I don’t see the supernatural as something over against the natural. Rather I see the world of our ordinary experience as a small part of a large spectrum which we humans have only limited capability to perceive, and a significant part, perhaps even the major part of that spectrum is non-material or what we call spiritual. This spiritual world is what I was referring to in the Night metaphor explored in the Tristan und Isolde piece I wrote last week. Naturalism prefers the Day, and assumes that whatever others might think of as composing the mystery of the Night is explainable in naturalistic or rationalistic Day terms. The Romantic and supernaturalist impulse gives precedence to the Night. It sees the Day world as this thin crust that floats on a sea of unfathomable Night.
I think most sensible people are open to that idea that our ordinary experience does not comprise everything there is. The argument today has more to do with accepting or discarding traditional beliefs regarding the nature of these dimensions outside the ordinary spectrum of human sense experience and in developing some criteria about what is real and what is delusional about what lies outside our normal experience in the Night world.
While there have always been skeptics about the supernatural, you'd have to say that most human beings in the history of the world have believed that there was such a thing. Even in the West until recently, there way pretty much universal acceptance of the idea that we humans are part of a larger spiritual reality. But there has been a rather significant cultural shift since the middle of the 19th century in which this traditional understanding about human connection with a larger spiritual world has met with much broader skepticism by the culture’s educated class in the West.
I think the reasons for this are complex but quite understandable. On the one hand the new faith in Reason celebrated in the previous century began to take hold in broader circles, becoming the religion of these elites, and anything that smacked of the irrational was suspect and dismissed. Maybe there was a god, but he had nothing to do with the world down here. Religious traditions and beliefs were dismissed as superstitious, obscurantist, and unnecessary.
There was also the ecrasez l’infame argument that focused on the blatant corruption and power games played by the official Church, which de-legitimated any claims it made for itself regarding its spiritual authority. The people in the Church were playing the same violent power game as everyone else. They were obviously using their superstitions to instill fear in a master/slave game in which they asserted themselves as masters to everyone else in the social and political order as slave. Why should anything they say be believed? If anything, what they say should be actively opposed as an enslaving ideology.
Add to that the explosion of technological advancement and material prosperity in the West, which promoted the new religion of commodity fetishism among the culture’s more affluent (and aspirational fetishism among the less affluent), concerns about the now ever more remote spiritual world became far less important to the average bourgeois than they were for their ancestors.
Add to that the culture-wide mood of suspicion among intellectuals after Darwin, Marx, and Nietzsche that found it difficult to accept the validity of any of the traditional received wisdom. By the end of the 19th century the mood had completely reversed from the wildly exuberant romanticism of the early century, and you have a class of cultural elites finding itself incapable of believing anything. The best anybody could come up with was Nietzsche’s uebermensch who was a meaning-creating being to replace the older meaning-discovering being. Since there was nothing out there to discover, if there was to be any meaning at all, it had to be created by the self-constituting subject. Problem was one person’s meaning is a good as the next guy’s. If there is no transcendent Good, then good and evil is determined by those who have the power to define it.
Nietzsche would not have approved what the Nazi’s did to his philosophy, but I think he would have a hard time arguing that what they did with it was implicit within his basic ontology. His basic nihilistic assumptions about the nature of reality were the same as theirs. The Nazi’s simply applied his ideas in a way that suited their idea of the will to power—that which meant strength and greater life for them and for the German nation. In a world defined by the will to power, who’s to say what’s the right interpretation of N’s thought except him who has the power to impose his view on everyone else?
But I bring this up here because it illustrates the problems with any moral philosophy that operates within closed naturalistic limits. As Dostoyevski’s Ivan says, anything is permissible, and who’s to say it’s not? If there is no transcendent Good, what grounds has anyone to resist what the powerful say is real? On what ground is there to stand outside the system as determined by those who hold the power? And if someone thinks differently, why should he pay the price to assert his thinking? Because of some obscurantist notion about the dignity of the truth-loving individual? It wouldn’t take long for the powerful in a closed system, if they got hold of such a believer, to convince him he was laughably delusional.
So what are the pros of Naturalism vs. the pros of openness to Supernaturalism? It seems to me you have to fall into one camp or the other. Which camp do you fall into? Nietzsche and Heidegger tried to avoid the either/or here, but in my opinion they create more problems than they solve and both--especially Nietzsche--are talking about a closed system. So anyway, these are the main pros/cons ideas that occur to me now, which are hardly exhaustive. I invite readers to add to them. I might add to them later in updates if something comes to mind.
Naturalism Pros:
• Simpler, cleaner in the Ockham's razor sense. Starts from below with what we know from within the closed sphere of the average human’s experience.
• Doesn’t require believing improbable things that don’t make sense within this closed sphere or wasting one’s time with puzzling over obscurantist nonsense wondering whether there’s anything to them.
• Avoids problems with infallibilism and the kind of violence groups throughout history have inflicted on other groups because their improbable beliefs differed from their own improbable beliefs.
• If supernaturalism were universally rejected, people would be forced to look at the world as it really is instead of living in fantasies that feed an infantile need for security.
Supernaturalism Pros:
• Open to a broader range of experience including experiences the people who have them identify as of the supernatural. Not dogmatically dismissive or reductionistic about experiences that don’t make sense within naturalistic parameters.
• Open to the possibility of the human project being purposeful rather than just some implausibly random occurrence. Answers the ‘why are we here’ question, which is not possible within the limitations of naturalism.
• Provides metaphysical validation to moral projects. Gives moral heft and gravity to human actions not possible within naturalist system. If the human project is fundamentally purposeless and if the Good is simply what most people complacently define it to be, why bother to do anything that costs too much?
I think that either alternative cannot reject or deny well-established evidence, but ultimately we’re in the realm of mythos rather than logos here, and the winning narrative goes to whichever narrative most robustly and plausibly explains human experience, answers fundamental human questions, and lays a foundation for costly moral action.