Scientific Naturalism: A Presentation at DaytonaCFI

I have a feeling of carrying coal to Newcastle —as the Brits might say—when I address this body about Scientific Naturalism. We should probably trade places, with my perking my ears and your speaking, but let me try:

Basically, naturalism contrasts with supernaturalism or better: with dualism. I do not believe that any philosopher has ever tried to discard the view that something natural was about us. One might think that perhaps the view of George Berkeley got close in that Berkeley argued for ideas only and for constancy in that realm of ideas only by virtue of constancy in the all-observing mind of God. However, we may assume that Samuel Johnson’s criticism is appropriate when he, kicking a rock, said, “Thus I refute Berkeley .” We may assume indeed that Berkeley walked around tables, chairs, and walls and not through them, thus admitting of some kind of external reality or nature.

Thomas of Aquinas, in fact, though a saint, was a fairly thorough empiricist, insisting, “nihil in intellectu quod non prius fuerit in sensu” [nothing is in the intellect which hasn’t been before in the senses]. And for anything to be in the senses, something must be out there beyond my thoughts.

So, any supernaturalism is indeed dualist in nature, asserting that the natural world can in some way be affected by what is outside of the natural world altogether. Creationism, for example, is dualist; a belief in souls is dualist; a belief in an afterlife is most commonly dualist also; most god-beliefs are dualist.

What I found intriguing is that Greek philosophers before Socrates and in the Aristotelian tradition after Socrates generally are not dualist. There is no reference to a god or a realm other than the natural in any but Plato. Plato’s notion of the realm of the forms and the ideal, then, blossoms with Christian content in much of Christian thought. Greek philosophy seems to talk about assertions that all is water, that all is ether, that all is number, that all is fire—but not generally that soul and body are in some way separable. Even the Greek gods appear to be supermen, not creatures of a supernatural realm. They are in most respects very human.

Dualism blossoms with Descartes (1596 to 1650). He believed that body and soul were separate entities, that humans were endowed with soul, and that animals did not have any souls. You are probably aware of the causality problem that Descartes’ view gives rise to. If a spiritual substance is to causally affect a physical substance, there must be some point of connection between the two realms. You may remember the scholarly debate about how many angels, who consist of spiritual substance, can dance on the tip of a pin, which is of physical substance. Since spiritual substance displaces no physical space, an infinite number of angels can dance on that pin, of course. You realize that there is a problem with the interplay of these two realms. But the interplay must happen since our souls will go to heaven if they have been engaged in morally clean lives while our bodies decay somewhere. Since the soul is being judged on its goodness or vileness, the soul must have had some opportunities to guide that miscreant body into right action. And so soul and body must have interacted if the divine judge is going to be a just one. For Descartes, the point of interaction between body and soul was the pineal gland, a structure of which he knew no other function. As you know, the pineal gland controls a person’s growth by way of the release of growth hormones. Descartes didn’t know that. So for him, this gland was the connection between the spiritual soul and the physical body.

What was even more egregious was the belief that animals had no souls. Since pain was an expression of soul, Descartes believed that, while animals could display pain-behavior, they clearly—being soulless—could not experience pain in any real sense. So, Cartesian scientists and Descartes himself practiced vivisection—cutting up living animals to learn about anatomical features. Pythagoras, by the way, a pre-Socratic philosopher, cautioned against eating meat on the grounds of the transmigration of souls, also a kind of dualism, which, however, made souls part of nature and not of some abstract spiritual realm. He also believed, just in case you are interested, that souls can transmigrate into beans, which means that in addition to eating no flesh-foods, one should not eat beans either.

The utilitarian ethicist Jeremy Bentham [1748 to 1832] refocused such Cartesian assertions later by pointing out about animals, “The question is not ‘are they rational or do they have souls?’; the question is ‘can they feel pain?’” Even in some religions the view is that only the faithful have souls and that, thus, the infidel does not enjoy the same ethical privilege as the believer.

Dualism, thus, has had some strange results in terms of human behavior, but the strongest of all is that a sensible philosophical view has not been able to assert itself in the commonsense of this culture. When I ask a group of students in a philosophy class, I rarely find any one student who does not believe that s/he has a soul. Never mind all the improbabilities of such a view. So, why has a non-dualistic, single-nature view not asserted itself yet? It’s not the case that philosophers have not tried. Philosophers of the so-called Vienna Circle , centered on Ludwig Wittgenstein, asserted a naturalist view. Wittgenstein said that whatever we can say, we can say clearly; but what we cannot talk about, we might as well shut up about. He has a point, when I reflect about those folks who try to tell me about the wisdom of God or God him/herself as something that transcends human understanding. You want to shout at them, “So, why don’t you shut up if you admit that you don’t know what you’re talking about!”

The core piece of the Vienna Circle or Logical Positivists, as this philosophical school was later dubbed, was the verifiability criterion of meaning.  Briefly, anything is nonsense unless it is either directly or indirectly verifiable. Let me illustrate:

            It is raining outside.

As I write this statement, it is not true. I can look outside to see trees with dried-up leaves and a brown lawn. I know that it is not raining and that it has not done so for a goodly while.  As I speak now before you, circumstances may be different. Either way, that statement is directly verifiable. I can look, determine that certain conditions do or do not obtain, and classify the statement as either true or false. That’s direct verifiability.

Contrast this with:

            Colorless green ideas sleep furiously.

What conditions will one look for? No idea? Me neither. The statement is nonsense and thus not worth my while.

Indirect verifiability works differently:

            Litmus paper held into acid turns red.

Now, note that I did not say: “This piece of litmus paper held into acid will turn . . . etc.” I speak of a general rule here. How often must I repeat direct verifications of specific statements before I can conclude the general statement to be categorically, though indirectly verified? A brief reflection will show you that we are here dealing with probabilities, not with actualities. And a probability may be increasingly corroborated without ever being completely verified.

Consider also “killing is wrong” or “the sunset is sublimely beautiful.” How do I verify such statements? I can throw out all scientific inquiry as non-verifiable and thus nonsensical. I can also throw out all ethics and aesthetics as nonsensical. But such conclusions about ethics and aesthetics seem not really satisfying answers. I suppose I could salvage ethics and aesthetics as reports of internal states of speakers.  “Killing is wrong” would thus become “I disapprove of killing.” And “the sunset is sublimely beautiful” would become “My heart beats faster when I see light refracted through the atmosphere from the setting sun.” But such translations are likely to trivialize such thoughts.

The most profound thinker of the 20th century was Sir Karl Raimund Popper. He actually had connections to the Vienna Circle . In his The Logic of Scientific Discovery, Popper sets up a demarcation of falsifiability between scientific thinking and fuzzier thinking. Falsifiability works better than verifiability to tell sensible statements from nonsensical statements. Let me illustrate:

            It is raining outside.

Now suppose I’m in a dark and deep dungeon where I can have no idea what’s going on outside at all. Do I still have a sensible statement? To decide that the statement is meaningful, I merely need to ask myself under what circumstances I would consider that statement to be false. Well, if I were to be able to look out of a casement of my dungeon and would see drought-punished trees and brown lawns and a cloudless azure sky, then I would be able to say that the statement is false. To decide that the statement is meaningful, I merely need to know under what circumstances I should say that the statement is false; I need not actually say that the statement is false. And so I clearly know a falsification instance of the statement and thus consider it meaningful.

Let’s look at the litmus paper.

            Litmus paper will turn red in acid.

Under what circumstances will I say that the statement is false. No problem, right? The statement would be false if and only if I have litmus paper—no cheap or deceptive imitation—and acid—no cheap or deceptive imitation there either—and the paper comes up green or colorless or black or whatever––other than red. Is that every likely to occur? I do not know nor do I need to know. All I need to do is to acknowledge that I will consider the statement to be false if the conditions were ever not to be as described by the statement.

How about this one?

            Colorless green ideas sleep furiously.

Nonsense statements such as this admit of no falsifying circumstances, simple because one would have no idea what to look for. For that reason, any debate about whether these colorless green ideas do or do not sleep furiously is doomed to failure. It will not get anywhere because we have no conditions under which anyone will retract anything here.

Now let me look at creationist doctrines. Suppose I say:

            The earth was created by an intelligent designer six thousand years ago precisely as it is now.

Human knowledge can only progress if one admits to conditions under which one will retract a statement. Clearly, a fossil in layers of sediment and a seemingly developmental sequence of fossils as well as similarities of DNA sequences are going to be falsifying instances of such a statement. It is a case of fundamental dishonesty not to own up to such falsifying instances.

One can pad a theory also; after all, I can assert that the world was created four minutes ago with all the memories or falsifying instances such as fossils inserted playfully. But that is a case of dishonest nonsense. Part of scientifically honest discourse is the admission of falsifying instances of what one asserts; creationists do not do that. During a debate, Hovind, the creationist of dinosaur-land fame, asserted that a universe without beginning cannot be thought, he concluded that, thus, God must be as creator of the universe. Such a view is dishonest, for God, too, is then without a cause, and the problem then has merely been shoved back one step without really answering the fundamental issue here. Hovind’s answer was that he knew of God’s agency and God’s self-caused existence by faith. But faith does not help toward any such analysis. Besides, if God is benevolent, the heartworm makes no sense, Siamese twins make even less sense, sundry acts of cruelty in nature, all make little sense and would count as falsifying instances of the assertion that a benevolent and all-powerful creator created the universe. S/he either did not create it or is not benevolent. Going by faith or subscribing to facts beyond human understanding is simply dishonest.

The German existentialist Karl Jaspers suggests that one should treat religions as botched metaphysics and criticize them without hesitation. Both religion and philosophy can benefit from such debate without reticence.

Now let me look at ethics and aesthetics briefly. Is such thought possible under conditions of scientific naturalism? With a view to falsifiability, I teach ethics as a way to challenge behavioral assertions—well, at least I do so for now; my employer appears to favor Christian ministers as ethics teachers. “There is no such thing as Christian ethics; ethics is a phenomenon of this world.” Radical, isn’t it? But that statement comes from Dietrich Bonhoeffer’s lecture on basics of Christian ethics, a lecture he delivered when ministering to a German congregation in Barcelona in the 1920’s. Let me put this in different terms as stated by a slightly less formidable philosophical character. In the film “Ice Age,” the saber-tooth tiger falls into a crevice of the ice. The mammoth reaches down into the crevice with his trunk and extracts the tiger. “Why did you do that?”, the tiger asks.—“That’s the way it’s done in the herd,” answers the mammoth.

One has no need for ethics if one were to inhabit a point of complete isolation. The social context of a herd imposes standards of behavior as a consequence of the common interests. I would say in the simplest terms that as a social being, I have an obligation not to do unjustified harms. Why is that so? I can justify that statement from a very simple enlightened self-interest, realizing that what goes ‘round comes ‘round. At this point, I am back at falsifiability as a standard of debate. Under what circumstances will I say that the statement “Killing is wrong” translated into “Killing person X harms person X” is a false statement. Where person X is rational and begs me to kill him or her, the statement is probably false. If I have evidence that person X is irrational, I may have to dig a bit more into the facts to determine the truth conditions of the statement. Think of euthanasia cases to see where this kind of reflection applies. Border cases between irrational requests of, say, a severely depressed person and reasonable requests for euthanasia are not easy to decide, but these problems are solvable by standards of normal logical reasoning and observation of related facts.

Doonesbury, I believe, has poked fun at the screaming zygotes that an inhabitant of the White House hears loudly as opposed to the screaming in Iraq that said inhabitant of the White House seems unable to hear. Again, these may be border cases, but they are not irresolvable when one analyzes the facts. In other words, these are factual problems, not abstract problems of metaphysics. What makes some ethical decisions a bit difficult at times is the fact that scientific observation makes ethical decision-making more difficult. A strange example is the strong moral constraint against male masturbation. At one time, people seriously believed that the sperm was a ready-made human being. One merely popped it into a warm place to let it grow; other than that, a mother had no particular biological contribution. You can readily see that deep thinkers at that time would conclude then that male masturbation was a form of mass-murder. Well into the beginning of the twentieth century, people devised vicious rings with sharp spikes to be placed over the penis to avoid any kind of misguided play at night. I read a physician’s guide from the 1880’s in the Mennonite library of Berne , Indiana , that warned masturbators about emphysema-like symptoms and a miserable death at age 20 if the no-masturbation rule were not to be observed meticulously. Well, today we know better, and many of those taboos have fallen by the wayside. Factual information made the difference.

Today, we have strong constraints against abortion for many of the same reasons. The religious view is that ensoulment happens at fertilization—never mind that the medieval Catholic church did not believe any such thing since spontaneously aborted fetuses were not given emergency baptisms; instead, people were told that these were not human beings yet. In fact, the medieval church asserted that no fetus was viable until after forty days for boys and eighty days for girls. But today, ensoulment happens at conception. Peter Singer offered an amusing reflection about that: Suppose a zygote is properly implanted and thus has a soul. Let’s call it Tom. Now we know that maternal twins are derived from a zygote that decides to split. We now have two implanted zygotes; let’s call them Dick and Harry. Does Dick get Tom’s soul? Is Tom’s soul taken back and two new souls are being issued? Do the souls split between Dick and Harry? How do we explain that from the vantage point of immediate ensoulment? The point is that a reflection about facts will help us along with making statements about ethics. Scientific insights will help our ethical stance fundamentally. Once translated into factual statements, ethical statements also are subject to falsifiability criteria as is any scientific statement.

Aesthetics is no different, I think. All statements about sublime beauty are translatable into falsifiable statements about balance, symmetry, and form without our losing any of the joy of observation.

Ethics, in fact, gains urgency through scientific naturalism. Deprived of eternity, we must get things right in this world. And if we are at the bottom of the wheel of fortune, we will not be calmed by promises of pie in the sky. Once I begin to realize that US-America has access to 60 percent of the world’s resources while having a mere 6 percent of the world’s population, I sense great urgency to change the wrong of huge gas-guzzling SUV’s in favor of the right of reliable supply of water in, say, Ethiopia. Once I realize that an animal’s DNA and physical circumstances are only minimally unlike my own, I sense great urgency to change the wrong of flesh-foods to the right of unharmed living for all sentient beings. As individuals, we rarely have more than a century to get wrong things right. And if the avoidance of harm is central to our ethical intent, then greater urgency will motivate the scientific naturalist than the religious millennialist or eternalist.

Finally, let me point out that scientific naturalists must preserve their humility. Religion answers all questions with certainty and truth—even those questions that religion cannot possibly answer or test because their comprehension transcends human understanding; we, on the other hand, must learn to live with ignorance.

The German existentialist Karl Jaspers referred to the “all-embracing” as a kind of event horizon of all that is and from which all that is seems to arise. We know of that all-embracing, but we do not know its nature and so must live with ignorance. Why does anything grow, develop, urge into being, take shape? We do not know, and we must live with that ignorance. Why, at the same time, does all that has taken shape fall apart again into entropy? We do not know, and we must live with that ignorance. The Hindus picture this urge to become from chaos and the urge to decay into chaos as Shiva, the maintainer and the destroyer. Clearly, they have a metaphor here that accepts ignorance and stands in awe. We cannot do better.

And then we contemplate the world around as objects that dissolve into molecules, that dissolve into atoms, that dissolve into quarks, that dissolve into strings, into vortices, into dark matter, into who knows what else. This regression ultimately highlights the tentative progress into a kind of epistemological abyss of theories. At that point, we begin to feel the awe of living with ignorance—and to be strong enough to bear it.