Presuppositionalism and the Interpretation of Homology
The Inseparability of Science and Philosophy
By Benjamin C. Stegman
The purpose of this paper is neither to attempt to prove that evolution does not occur nor that common ancestry does not exist. Such a subject is far beyond the reach of such a short treatment as I would be able to render within this space. Rather, the purpose of this article is to show how the interpretation of homology, and indeed the entire subject of comparative morphology is based completely upon the presuppositions one holds.
As any good student of comparative morphology knows, homology is the study of similarity. From the Darwinian evolutionist’s vantage point, it is the study of common lineage. The discipline of homology has been around a long time. According to Jonathan Wells and Paul Nelson of the Access Research Network, (1) "...from at least the time of Aristotle, people who study living organisms have noted some remarkable similarities among very diverse creatures." The authors cite several examples, including "...bats and butterflies ...[being]... quite different from each other, yet both have wings to fly; bats fly and whales swim, yet the bones in a bat's wing and a whale's flipper are strikingly alike."
All science is based upon inductive reasoning, that is, inference about a general model based upon a repeated specific incident. Inductive reasoning can never operate without pre-existent assumptions since it is assuming that a specific part is a representation of the general whole (This is different from deductive reasoning, which is the use of necessary inference to make a conclusion based upon a pre-existent premise. I.e. the conclusion is pre determined). This is demonstrated quite succinctly by the familiar scientific method wherein we obtain experimental data via observation so as to make inferences about a sampled population. This may seem obvious, but there are some interesting ramifications associated with this fact that need to be addressed. First, science can never lead to truth, only probability. In private correspondence with this author, Hans and Nathaniel Bluedorn (2) , nationally recognized authors of various books on logic and reasoning, comment: "...when it comes to science, you can never prove anything for certain. You can only increase the level of probability though various methods of inductive confirmation." It is by definition impossible to "prove" something scientifically since truth cannot be obtained through inductive reasoning. The Bluedorns go on to state that "...even any method of evaluating the probability of something is based on assumptions about what makes something more probable or less probable." It should be obvious then that it is necessary for scientists to "...assume all sorts of things about the universe [as well as] their ability to observe things when they try to show that some theory is probably true." This then leads to the second ramification: science requires a philosophy if it is to be meaningful. This may sound like a very presumptuous statement, but let me elaborate a bit. All arguments aside, human minds must exist in a reality or truth (perceived or otherwise) in order to accomplish meaningful thought.
In other words, reality and truth must be assumed to exist if we are to get anywhere in this or any other discussion. Given this fact, and since science discovers only probability, a frame of reference must exist outside of scientific inductive reasoning. Now I grant that there are probably as many frames of reference as there are scientists, but my point is that every scientist has one, and must have one in order to make any kind of meaningful interpretation of data. If we wish to make any real inference about an event that occurs tomorrow or the next day based upon an observation obtained today, we must assume that the universe demonstrates continuity, e.g. the effect of the law of gravity on a falling object will still be the same tomorrow and the next day, and the next, etc. In short, I must possess a philosophy that allows me to assume that the universe (or at least the part where I am) will demonstrate continuity.
It may seem that I have chased a very long rabbit trail, but I’ve written all this for one reason; that is to validate the following claim. That is, interpretation of any part of science is by definition based upon the scientist’s frame of reference, i.e. his presuppositions. As Hans and Nathaniel Bluedorn go on to state in their previously cited correspondence: "...When scientists use the similarity in the design of animal body parts to support common ancestry those scientists have every right to their opinion. When scientists use their theory of common ancestry to interpret the similarity of design, they are only being consistent with their theory. They observed similarities, they developed a surmise that all animals descended from each other, they went back and observed even more similarities that seemed to confirm their surmise, and they developed even more theories to explain all this. ...The fact that someone can develop a theory to explain something does not mean that theory is true. Even if this theory has no internal contradictions, and does explain the evidence in a plausible way, this does not prove it is true. ...Induction is totally meaningless ... [it] can’t arrive at anything, even probabilities..." without presuppositions regarding ourselves and the world around us.
This is also true of those scientists who feel that homology is better explained by the concept of intelligent design. One camp may feel that "the watchmaker is blind", while the other may feel just as strongly that information requires an Intelligent Designer. The sides are separated not by their science, but by their presuppositions. In conclusion, although the interpretation of homology and comparative morphology is still a great subject of debate, I have tried to show that the existing controversy has never been based upon a disagreement between science and philosophy, but between the presuppositions of the opposing parties. It is the opinion of this author that the presuppositions of the intelligent design movement are more logically consistent with reality that those of the common ancestry camp, but that, alas, is another subject for another time.
1: Nelson, Paul and Jonathan Wells: “Homology: A Concept in Crisis” Access Research Network, an intelligent design information resource: http://www.arn.org
2: Bluedorn, Hans and Nathaniel: private correspondence with the author. Business website can be viewed at www.triviumpursuit.com and www.christianlogic.com