by Gene Callahan
“The theorist who drops anchor here or there and puts out his equipment of theoretic hooks and nets in order to catch the fish of the locality, interrupts but does not betray his calling. And indeed, the unconditional engagement of understanding must be arrested and inquiry must be focused upon a this if any identity is to become intelligible in terms of its postulates. An investigation which denies or questions its own conditions surrenders its opportunity of achieving its own conditional perfection; the theorist who interrogates instead of using his theoretic equipment catches no fish.” – Michael Oakeshott, On Human Conduct
We often hear controversy today over whether something is a “fact” or a “theory.” This arises both in the debate over anthropogenic global warming and in the disputes between creationists and Darwinists: Is global warming a “proven fact” or a “speculative theory”? Is evolution a “scientific fact” or “just a theory”? For instance, at globalwarming.com, I find the statement: “While some would call global warming a theory, others would call it a proven set of facts.”
Or, at the About.com entry on atheism, there is the claim:
“In reality, evolution is both a fact and a theory.
“To understand how it can be both, it is necessary to understand that evolution can be used in more than one way in biology. A common way to use the term evolution is simply to describe the change in the gene pool of a population over time; that this occurs is an indisputable fact.”
Wikipedia offers a similar (I say similarly misleading) explanation of the distinction between theory and fact concerning evolution:
“The ‘fact of evolution’ refers to the changes in the genetic material of a population of biological organisms over time, which are known to have occurred through scientific observations and experiments. The ‘theory of evolution’ refers to the modern evolutionary synthesis, which is the current scientific explanation of how these changes occur.”
Chemist Michael Blaber defines a fact as “An indisputable truth,” as above about.com seems to do as well. He offers, as an example, “It is a fact that on June 30, 1908 in Tunguska, Siberia, an explosion equivalent to about 15 million tons of TNT occurred.” But this is certainly not indisputable! What we have are certain historical reports of people hearing an explosion, of trees being flattened, and so on, as well as a crater. These are the basis of an historical theory that there was such an explosion. Now, scientists can accept that theory as a fact and go on to investigate why it occurred. But they also could question this conclusion — perhaps people were mistaken about the day the explosion occurred. Perhaps they were subject to some form of mass hysteria.
Whether something is a fact or a theory is not, in itself, a matter independent of the judgment of the person using the term. x is a fact for me if, for the purposes of devising my theory, I am going to take the proposition asserting x as unproblematically true, while x is a theory for me if I am investigating the basis for asserting it. Thus, when I am doing work on constitutional theory, I take the proposition ‘Rome had no written constitution’ to be a “given” fact, because it is the universal conclusion of historians investigating that time, because I am not attempting to do original historical research, and because one has to start somewhere, and that somewhere is always a given in experience. On the other hand, for an historian who feels she may have uncovered some startling new evidence that Rome did have a written constitution, the proposition that it did not is a theory and not a fact.
In terms of the evolutionary discussion from Wikipedia, “the changes in the genetic material of a population of biological organisms over time” are not facts because they “are known to have occurred through scientific observations and experiments,” but because, for the purposes of formulating a theory of evolution, we accept the propositions concerning these things as givens. But these “facts” are theoretical when seen from the perspective of, say, a theory of how to detect genetic changes that occur over time, or a theory of what, exactly, constitutes a genetic change.
Similarly, for a scientist investigating global warming, the temperature readings of thermometers will be facts. (He might question whether the thermometers were placed in the right spots, but it is highly unlikely he will question them as thermometers. To do so would ensure that he would make little progress on the topic of global warming.) On the other hand, someone working on the theory of temperature-measuring devices will not accept these readings as facts about the temperature, but as theoretical statements about the relationship between the temperature and such a device.
Even the most ordinary, “plain” facts can become theoretical under the right circumstances. As I am typing this, I can look out my window and see a snow-covered tree in front of me. (Yes, a tree grows in Brooklyn!) Ordinarily, the proposition “There is a tree in front of me” is about as factual as propositions can get. But, should I suspect I have been slipped a powerful mind-altering substance and am having my perceptions deliberately manipulated, I may come to regard “There is a tree in front of me” as a theoretical proposition calling for further investigation. Or seeing a red wall in front of me, it may appear an obvious “fact” that the wall is red. But should someone point out that the room is lit by a red light, that fact may appear much more theoretical. Indeed, the whole philosophy of Descartes was built upon treating as theoretical all of the “plain facts” of ordinary life.
Thus, the distinction between fact and theory is not one of the certainty of the proposition(s) involved, but one of the attitude of the researcher towards the proposition(s). The germ of truth in the mistaken idea that “facts” are certain while “theories” are speculative is that a higher degree of justified belief in a proposition often will make it more likely that a researcher in a “higher-level discipline” will treat it as a fact to be used and not a theory to be questioned. But there are times when it makes sense to question a well-established “fact” and treat it as a “mere” theory (as Einstein did with Newton’s absolute space-time), and other times when it is sensible to take some speculative theory as a fact and see where that gets us.
So the question “Is global warming a fact or a theory?” should be answered “It is both,” but not because some “parts” of it are factual and others are theoretical, but because all propositions can be treated as stating facts or theories.
For those working on the science of global warming, it is and must always remain a theory. Now, perhaps someday the theory will be so well accepted that no one bothers to work on it anymore, and then it may be called “a simple fact.” Of course, even then, someone may call it into question anew, as happened with, say, Newtonian mechanics at the beginning of the twentieth century.
For someone developing a theory about what the proper public climate policies should be, there is a choice as to whether or not to take anthropogenic global warming (AGW) as a fact. That choice will involve many factors, such as evaluations of the possible bias of researchers, evaluations of the consequences of wrongly regarding AGW as factual and those of wrongly regarding it as non-factual, and more.