Fact or Theory?: Getting it Right

Recently, I met a college student whose professor had told her that it is a fact that all living organisms are descended from a single life form. I quickly informed her that her professor was wrong-- that is not a fact, it is one hypothesis that stems from the theory of evolution. However, lest this student use the idea that evolution is “only a theory” to dismiss it entirely without giving it an honest look, I hastened to add that a theory, or even a hypothesis, is far from being a guess. I later wished that I had had time to explain the difference between fact, hypothesis, and theory-- for all of these have definitions in science, which differ from how they are often used in the vernacular. So, in regret that I cannot explain it to her in person, I will explain it here, hoping it will be helpful to someone else whose professor has made or will make the same mistake.

First, fact:

I love what one of my old ecology textbooks says about this: It defines facts as “particular truths of the natural world” and then goes on to state, “The notion of truth is a profound one that philosophers discuss in detail and scientists just assume is simple. Truth consists of correspondence with the facts.” (Krebs 2001:13, 14)

This sounds circular, but it’s really just saying that facts are things that are true. Furthermore, facts are true whether or not we know or understand them correctly:

“[scientists] make observations, which may be faulty, and consequently every observation is not automatically a fact.” (Krebs 2001:13)

The UC Berkeley “Understanding Science” website defines it this way:

“Fact: Statement that is known to be true through direct observation. Since scientific ideas are inherently tentative, the term fact is more meaningful in everyday language than in the language of science.”

In other words, in the actual doing and reporting of science, “fact” isn’t a term we use a lot. (Also note an idea we discussed in a previous post, that scientific knowledge is tentative.) Here is a very relevant example:

"[In] scientific thinking ...we can only be completely confident about relatively simple statements. For example, it may be a fact that there are three trees in your backyard. However, our knowledge of how all trees are related to one another is not a fact; it is a complex body of knowledge based on many different lines of evidence and reasoning that may change as new evidence is discovered and as old evidence is interpreted in new ways. Though our knowledge of tree relationships is not a fact, it is broadly applicable, useful in many situations, and synthesizes many individual facts into a broader framework. Science values facts but recognizes that many forms of knowledge are more powerful than simple facts.” (UC Berkeley link above)

Hm, what an intriguing statement! Knowledge that is more powerful than facts? Read on!

Next, hypothesis:

Once a scientist has some observations in hand, he/she formulates a possible explanation consistent with everything else he/she already knows. This possible explanation is a hypothesis, and it must be stated in a way that allows it to be tested by experiment or further observation. A hypothesis makes predictions about future observations, and if these predictions are actually observed, the hypothesis is supported. Observations contrary to the predictions would help refute the hypothesis. Remember that testability and falsifiability are flip-sides of the same coin; for a hypothesis to be scientific, it must be possible in principle to gather evidence that would support or refute it. (See more on testability, and see “Falsifiable” here for further clarification of these terms.) Even so, we can never prove or disprove a hypothesis with absolute certainty.

Finally, theory:

Again, the Understanding Science project summarizes well (they make my job a lot easier!):

“Theory: In science, a broad, natural explanation for a wide range of phenomena. Theories are concise, coherent, systematic, predictive, and broadly applicable, often integrating and generalizing many hypotheses. Theories accepted by the scientific community are generally strongly supported by many different lines of evidence-but even theories may be modified or overturned if warranted by new evidence and perspectives.”

And (still quoting from the above link) here is a further point I wish to emphasize:

“Occasionally, scientific ideas (such as biological evolution) are written off with the putdown "it's just a theory." This slur is misleading and conflates two separate meanings of the word theory: in common usage, the word theory means just a hunch, but in science, a theory is a powerful explanation for a broad set of observations. To be accepted by the scientific community, a theory (in the scientific sense of the word) must be strongly supported by many different lines of evidence. So biological evolution is a theory (it is a well-supported, widely accepted, and powerful explanation for the diversity of life on Earth), but it is not "just" a theory.”

Nor, I would add, is it as simple as fact. A theory, by definition, is an overarching, explanatory idea that rests upon numerous facts and hypotheses. It is a BIG, HUGE, elegant idea that squares (at least so far) with many facts we have in our possession… insofar as we can tell that they are facts. A theory is also generative, spurring new hypotheses and avenues of research in an organic, ongoing process that is never complete. And, as with any scientific idea, some aspects of a theory may turn out to be right, and some may turn out to be wrong-- and we can’t tell the difference yet. Moreover, a theory can remain well-supported and valid as a research scaffolding, despite the incompleteness of some of its sub-elements. For example, it may turn out that we have correctly understood the basic laws of inheritance that lead to genetic changes in a population over time, while a complete family tree linking all life forms to a common ancestor remains elusive. Both of these ideas fit under the umbrella of “The Theory of Evolution,” and either of them may (and probably will) be modified as our understanding… er, evolves. Hence, no one who understands the breadth and dynamic function of theory would be so simplistic as to equate it with fact.

So… the next time someone tells you that evolution is a fact, you can tell them with great enthusiasm that on the contrary, evolution is not a fact; it is much more than only facts-- it is a theory! How exciting is that?! (You may want to explain this using large hand gestures, indicating that, in science, theory is a BIG thing compared to fact.)

And then, if they ask you whether you believe in it, you can tell them that while a theory is well supported by multiple lines of evidence, putting absolute faith in a scientific theory is not scientific. No one can fault you for refusing to commit your final opinion, because science does not have the final word. And that’s a fact.

Fertile Common Ground: Conservation

The stated purpose of this blog is to promote positive interactions between science and religion. While several of my posts have focused on how to avoid conflict (by noticing how it has been generated), today I’d like to focus more directly on positive interactions that are already taking place. If evolution has been the most contentious topic between science and religion, then certainly the topic of greatest agreement and cooperation between them in recent years has been biological conservation.

Many of the world’s religions are recognizing that the teachings of their faith prompt them to care for our planet and the life upon it. Religious leaders around the globe have taken an increasingly active role in encouraging their fellow believers to act responsibly with respect to our environment. Numerous organizations have formed to promote cooperation between religions and conservation groups. Here are two of the most prominent organizations, whose websites contain a wealth of information about religions and the environment: Alliance of Religions and Conservation and the Forum on Religion and Ecology at Yale.

From 2008-2011, I was fortunate to have the opportunity of serving on the board of the Religion and Conservation Biology Working Group, a sub-group of the Society for Conservation Biology. During part of this time (until the birth of my youngest child), I was chair of the curriculum committee, and we were charged with writing materials to serve as a starting point for cooperation-- a bridge-- between conservation professionals and religious groups. We wrote articles introducing religious groups to the views and goals of conservation professionals, and vice versa, as well as a series of Fact Sheets summarizing the positions of seven of the world’s major religions regarding the earth and the environment. (These are all available at the Religion and Conservation Biology resource page.) I remember writing the last of these summaries just a few days before my son was born-- whew!-- and I was grateful for the opportunity to contribute to this worthy effort.

As I complied my research for these summaries, I noticed a pattern: The Abrahamic religions (Judaism, Islam, Christianity) centered their conservation ethic around the idea of stewardship-- that God, the Creator, has given us charge over his creations and holds us accountable for our use of them. Those religions whose beliefs include reincarnation (Hinduism and Buddhism, for example) centered their conservation ethic around the ideas of nonviolence and the interconnectedness of all life. And Eastern religions such as Confucianism and Daoism tended to focus on the balance of nature and our proper place and action within it. It is interesting to note that, while the core concepts leading to a conservation ethic may be different for each religion, every major world religion contains strong internal motivation for environmental responsibility. These are not values that have to be imposed from outside; they are already there and, interestingly, always have been. Often it is the most ancient of teachings that have lended themselves most effectively to a revitalized concern for nature. It is to the credit of these religions that many of their number have allowed themselves to be informed by modern environmental science and then have reached back into their own traditions to find a deeper motivation for improved action.

“And the reason I’m telling you this is because…” (Dr. Seuss) it demonstrates that when scientists and religious people have taken a step back to look respectfully and non judgmentally at each other’s beliefs and goals, they have found many common values and ways to work in cooperation. Hooray, hooray, that we don’t all have to hold the same worldview in order to work well together toward common goals! This fact gives me great hope for the future of mutual understanding and appreciation between science and religion.

To my fellow conservation scientists, I would say: Remember that Conservation Biology, as a discipline, is a marriage between a science (biology) and a value system (conservation). We are qualified to teach people the findings and tools of our science, but our moral authority to dictate value systems is no greater than anyone else’s. We must not expect religions to convert or adapt to a science-dictated worldview, and we must not present science as a moral authority on the environment. The wonderful news is that we need not (and should not) expect people to change their religious views in order to embrace conservation. Conservation is already proving to be a topic of agreement despite diverse worldviews, as long as we will work respectfully with religions to find common ground in our values. We can be more careful to avoid language that engenders strife and instead employ language with which religious groups can identify, such as “intrinsic value of nature,” “reverence for life,” and “stewardship.” We will meet with cooperation if we will remember what science is and have the intellectual honesty to report it accurately as a tool for understanding how things work, while respecting the diverse views of others regarding what people and societies should value.

To my fellow believers I would say: Let’s look to the best in our beliefs and traditions for motivation to care for this special planet, and then stand ready to listen to, learn from, and embrace the sound ideas and tools science can offer us for doing it more effectively. I, for one, am grateful that science can teach me biological principles that will help me be a better steward over my little corner of this beautiful earth. Trying to do so is part of my worship of the Creator.

Does Evolution Support Atheism?

After a long time away from my blog over the holidays (and beyond), I have been inspired (or provoked) to take up my pen (keyboard) again in response to a blog post I read by a fellow member of my faith. The author, Dave, cautioned that evolution contributes to atheism because of its materialism and “mechanistic underpinnings.” (Materialism is the philosophy that all that exists is matter, and mechanistic means explaining phenomena in purely physical terms). While he acknowledged that “There are no inherent problems with interpreting natural world events using a mechanistic-laden theory like evolution, as long as people recognize the limitations,” he maintained that danger arises “when they accept mechanism as reflecting the way the world really is, as a sort of ontological reality.” (Ontology, by the way, is a branch of metaphysics that deals with the nature and kinds of things that have existence.) While I think I agreed with the basic idea Dave was getting at, I was bothered by his claim that “the underpinnings” of evolution contribute to atheism. It struck me that the discussion could be aided by an understanding that science is based on one particular kind of naturalism (explaining things in terms of only natural causes and laws), and that philosophers recognize different types of naturalism: methodological naturalism and metaphysical naturalism. The first is a method or tool; the second is a philosophy. Let’s look at these more closely (bear with me through the philosophical lingo-- it will pay off!):

Methodological naturalism is methodical study of the natural or physical world that limits itself to natural explanations that can be empirically tested, observed and quantified. Here’s a lengthy quote about that, if you wish to read it (or you can skip it and still get the drift):

“Expert testimony reveals that since the scientific revolution of the 16th and 17th centuries, science has been limited to the search for natural causes to explain natural phenomena.... Since that time period, science has been a discipline in which testability, rather than any ecclesiastical authority or philosophical coherence, has been the measure of a scientific idea's worth. In deliberately omitting theological or "ultimate" explanations for the existence or characteristics of the natural world, science does not consider issues of "meaning" and "purpose" in the world. While supernatural explanations may be important and have merit, they are not part of science. This self-imposed convention of science, which limits inquiry to testable, natural explanations about the natural world, is referred to by philosophers as ‘methodological naturalism’ and is sometimes known as the scientific method. Methodological naturalism is a ‘ground rule’ of science today which requires scientists to seek explanations in the world around us based upon what we can observe, test, replicate, and verify.”-Kitzmiller vs Dover (2005:64-65)

In other words, methodological naturalism is what the scientific method is based on. The naturalistic “underpinnings of evolution" Dave refers to in his blog are exactly the same as the naturalistic underpinnings-- the scientific method-- that all of science is based on. We cannot conduct science in any other way. The Theory of Evolution is no different (or any more conducive to atheism) than any of the rest of science in this way.

Metaphysical or philosophical naturalism, on the other hand, claims that nature is all there is—that nothing exists beyond the natural world we observe. Metaphysical naturalism denies the existence of the spiritual and is therefore distinctly different than the methodological naturalism necessary for scientific inquiry, which must remain mute about whether anything lies beyond the physical world. And here is the key point: metaphysical naturalism is not part of science; it is a philosophy (taken on faith, ironically) entirely outside the power of science to confirm or deny. Hence, a religious scientist can be perfectly comfortable employing methodological naturalism in his science while firmly rejecting metaphysical naturalism. The problem is when people (and often scientists themselves) fail to draw the distinction. Others also recognize this problem:

“Methodological naturalism is distinguished from metaphysical (or ontological or philosophical) naturalism, the view that nature is all there is and that supernatural entities such as spirit and God do not exist. The former is a statement about the limits of science, while the latter is a statement about the whole of reality, but some philosophers argue that the distinction fails in practice because scientists tend to act as though the whole of reality is accessible to their methods.” –New World Encyclopedia (my italics. Quote found here)

Note that last line, to which I added italics. And now I’m sure you are saying, “Alisse, you are harping on the same subject again! We know, we know: science is a method limited to only some portions of reality, and problems happen when we try to take it beyond its bounds and turn it into a philosophy about all of reality. We get it, okay!” Good. I’m glad you understand this point, because I continue to find it at the root of most conflict involving science. In fact, this is the very thing that has led to the backlash against science in the U.S. For example, William Dembski, a prominent leader in the Intelligent Design (ID) movement, declares, “Intelligent Design entails that naturalism in all forms be rejected” (1998). He further states:

“So long as methodological naturalism sets the ground rules for how the game of science is to be played, IDT [Intelligent Design Thesis] has no chance… The ground rules of science have to be changed. We need to realize that methodological naturalism is the functional equivalent of a full blown metaphysical naturalism. Metaphysical naturalism asserts that the material world is all there is. …Methodological naturalism asks us for the sake of science to pretend that the material world is all there is. But once science comes to be taken as the only universally valid form of knowledge within a culture, it follows at once that methodological and metaphysical naturalism become for all intents and purposes indistinguishable. They are functionally equivalent. What needs to be done, therefore, is to break the grip of naturalism in both guises, methodological and metaphysical.” –William Dembski (1996). 

Wait. Did I hear that last line right? Because some people think the scientific method is the only valid way to knowledge, we should overthrow the scientific method? We should ignore the valid distinction, recognized by philosophers, between the two kinds of naturalism and throw the baby out with the bath water? That's certainly what he seems to be saying. Although I obviously sympathize with Dembski's concerns about people placing science on too high a throne, I find his solution baffling. He doesn't just want to dethrone science; he wants to dismember it.

As summarized in the court decision of Kitzmiller vs Dover, “ID violates the centuries-old ground rules of science by invoking and permitting supernatural causation" (2005:64). Let’s think about what would happen if we overthrew the ground rules of science-- of the scientific method that must leave questions about God alone-- and allowed all fields of science to address the “supernatural.” Everybody has different ideas about what is in that realm. Various untestable and unfalsifiable proposals of the supernatural would have to be entertained not just in biology and geology (the fields especially objectionable to ID), but in physics, astronomy, electronic theory, medicine, chemistry, engineering, etc., etc. Can you imagine the implications, here?  People could legitimately propose that invisible water fairies are responsible for hydraulic lift. In other words, attacking the theory of evolution by changing its “underpinnings” (scientific naturalism) has vast implications for how all of science—not just biology—would then be done. It would cease to be science as we know it and would resemble the more speculative versions of science known in previous centuries, before the formalization of the scientific method. You think I’m exaggerating, and yes, it all sounds ridiculous, but this is indeed the logical conclusion of rejecting methodological naturalism as Dembski suggests. It undoes science.

It seems abundantly clear that the real solution, which Dembski alludes to but does not pursue, is to emphasize that science is not “the only universally valid form of knowledge.” Instead, ID jumps on board the idea that science does provide the answers and sets about to disguise itself as a new scientific enterprise, all the while seeking to undermine the scientific method. I fail to see the logic in this approach, well-intended toward the "intelligent designer" though it may be.

Thank goodness, I say, for the naturalistic “underpinnings of evolution” and of science in general. Let’s just keep straight what kind of naturalism we are talking about. The Theory of Evolution is more likely to facilitate atheism (and a subsequent backlash against science) when its grounding in scientific naturalism is fundamentally misunderstood or ignored.