Logic, Logical Fallacies, and Rhetoric

In writing this book, it was my intention that it be for people who have no irrevocable position on at least some of the differences of opinion between creationists and evolutionists, but who would like a view of those arguments that is relatively fair. That I have not totally accomplished, as I am clearly an evolutionist and believe in the naturalist (materialist) view, whereas creationists do not. And therein lies the difference. I hope to have produced in this book a clear differentiation of the reasons for what evolutionists believe and what creationists believe, written at a level that intelligent high school seniors or college freshmen or sophomores can readily understand without their having taken any biology or theology courses. I am targeting that group because, in my opinion, it is the failure of scientists to present clearly what they do and why that has caused so many problems in our schools and courts. I welcome criticism from all parties, especially where I have done injustice to any view, and if this book survives to a second edition, I will correct those errors. I have included a short glossary to aid the reader in understanding some of the terms used in this book.

Not all biologists will necessarily agree with 100 percent of what I have to say. Nevertheless, I believe that the vast majority of evolutionists will agree with almost everything evolutionary that I present. Similarly, not all creationists will agree among themselves that my representation of their view is correct or complete, although the degree to which creationists agree among themselves may often be much less so. The point is that too often one side denounces the other for an opinion that has been given by a member of the opposing camp, even though the opinion being denounced has become rare and unrepresentative of current creationist or evolutionary thought, as the case may be.

Generalities are not intended to be 100 percent applicable, but if something is true 99 percent of the time, that something accordingly is important and frequently not refutable by describing a single exception. This is an example of the straw man fallacy, which takes an unrepresentative view of one's opponents and attacks that view, even though it is already recognized as unsupportable in its extreme form by those same opponents.

The principal goal is to establish what science is and how biological evolution is a scientific study, no matter what errors may be present at our current level of understanding of evolution. This is true even if Darwinian evolution itself should be proven wrong. In contrast, creationism, intelligent design, and irreducible complexity are not scientific, even if their conclusions (such as that God made the universe in six literal days about six thousand years ago) were shown to be all correct. It is my hope to represent the creationist viewpoints as those of people with different criteria for resolving important questions. Nevertheless, I hope that if people can understand what evolutionists do and how and why, they will understand that creationism is rarely if ever scientific. Biological evolution is almost always scientific, and thus the reader will understand why evolutionists oppose the teaching of this theological view as part of any science course.

I try to present both sides fairly in describing what strict creationists believe. In evaluating those beliefs, however, I shall rigorously apply scientific and theological methods as appropriate. For example, a creationist may say he believes that the Bible is the word of God and therefore cannot be wrong, that the Bible says the world was created in six days, and that he therefore believes that the world was created in six days. His logical argument in itself is quite valid (and we will elaborate further on chains of logic later in this chapter). Consider the following syllogisms. (A syllogism is a form of deductive reasoning consisting of a major premise, a minor premise, and a conclusion.)

Syllogism 1

Premise 1: The Bible (Old and New Testaments) is the Word of God.

Premise 2: The Word of God cannot be wrong.

Conclusion 1: The Bible cannot be wrong.

Syllogism 2

Conclusion 1: The Bible cannot be wrong.

Premise 3: The Bible says the world was created in six days.

Conclusion 2: The world was created in six days.

Note that Conclusion 1 is also the first premise of the second syllogism. But both of these premises are theo-logical, not materio-logical. They are theo-logical because the premises themselves are about God and God's Bible. This difference is crucial in that the starting premises of the creationist are not the same as those of the evolutionist. Hence differing conclusions should be expected, even though our rules of logic are (or certainly should be) identical. The problem of logic is sufficiently important that the majority of this chapter is devoted to logic for those who might enjoy a minimal refresher course on the subject of how we decide which conclusions are logically admissible and which are not.

Critics of evolution often claim that it cannot be correct because it occurs via random genetic mutations, and random processes cannot create order. It is true that mutations are random, because they are not directed by a force that guarantees that, given the ancestral form, the nature of the character can be predicted. But mutations are only half the story. Environmental pressures are directive, and this leads to what is termed natural selection. Biological evolution is the study of the origins of the diverse nature of living things. It was inspired greatly by Charles Darwin, who, in 1859, proposed a theory for the origin and diversity of the living world. It was, and still is, called natural selection, and it postulated that sources of variation (later to be called mutations) occurred in nature. Some variants/mutants were harmful and were weeded out. A much smaller number of mutants were beneficial and spread through the population. The mechanism of evolution was that more offspring were produced than the habitat could support, and thus many members of a population would not produce successful, reproductively viable offspring. Those that did, did so because of the favorable effects of the useful mutations. Note that the creation of the mutations is a random process, but selection of mutants with a beneficial effect is directional. It was natural to portray the history of life as a genealogy in a branching tree that showed who came from whom and approximately when.

Many devout Christians (and other religious people) find no conflict at all between natural selection and their religion. Evolution, they assert, is simply "the way that God did it." Nevertheless, many evolutionists' statements directly contradict a literal interpretation of some of the statements given in the...