We live in a world where many people simply do not reason rationally. They are not able to make a good, cogent argument for their position. This is sometimes seen in political or religious arguments. Such debates often have more heat than light. People have very strong opinions, and voice them with fervor. But often their arguments are simply not rational! The conclusions do not follow from the premises. Why is this? And what can we do about it?
Most schools no longer teach logic. Perhaps that is part of the reason why people are often so illogical; they have never learned. But I suggest that the root cause is even deeper. To be logical is to think in a way that is consistent with the nature of God. Logic is a reflection of the way God thinks, and the way He expects us to think. That is why laws of logic are universal and unchanging; they reflect that aspect of God. As our culture has increasingly rejected biblical authority, it stands to reason that people will increasingly reject logic. A rejection of logical reasoning shows up in two ways: arbitrariness and inconsistency.
To be arbitrary means “to not have a reason.” When you decide to wear a red shirt rather than a blue one, and you really don’t have a reason, such a decision is arbitrary. Or when you decide to drink grape juice instead of orange juice, if you have no specific reason in mind, then your choice is arbitrary. We make countless arbitrary and often unconscious choices every day. Did you start walking with your left foot or your right? It really doesn’t matter too much one way or the other.
There is nothing wrong with such a whimsical attitude when it comes to the subjective preferences. However, when consequences matter, we had better have a good reason for our choice. The decision of whether or not to wear a parachute when jumping from a plane will have a profound effect on the outcome. And so this is not a decision that we would want to leave to the flip of a coin. A jumper has a very good reason to wear the parachute: it will save his life. His decision is not arbitrary.
Likewise, when it comes to logic, we are not permitted to be arbitrary. This is the whole point of rational debate. The goal is to show that we have a good reason for our position, and that it is not arbitrary. In a debate, to be arbitrary is to concede defeat. It is to say, “I don’t really have a good reason for my position.”
Whenever a person says something like this, “I believe X and you should too”, there will be a natural question on the part of the hearer: “Why? Why do you believe X and why should I?” Now if the person is not able to give a reason for his belief in X, then there is no reason why the hearer shouldn’t believe the exact opposite.
Beliefs should always have a reason. The more important the belief, the more crucial it is to have a good reason, because the consequences are more devastating if you are wrong. Little children don’t often recognize this. They tend to be very arbitrary. They firmly believe there is a monster in the closet, and they act on their belief by pulling the bed sheets over their head. Do they have a good reason for their belief? Of course not. Children are irrational, and we expect this from them. As people grow up, we are supposed to become rational. We are supposed to learn to have good reasons for our beliefs. And we are supposed to discard beliefs that don’t have good reasons. This is the mark of rationality.
You may think that this is all perfectly obvious. And most of the time, it is. But in debates on origins, politics, and religion, you will find that people are often very arbitrary. And you will actually have to explain to them that this is not rational. They are supposed to be giving a good reason for their beliefs, not just stating them and getting upset when you don’t agree. The whole point of a debate is to see which side has the best reason for their respective position.
The other mark of rationality is consistency. Truth is always self-consistent. Therefore, if a person makes two claims that are inconsistent with each other, we can be certain that at least one of them is false. And it is irrational to believe something that must be false. A rational person’s beliefs and claims therefore will be self-consistent.
The most obvious types of inconsistency are those which are outright contradictions. Clearly, if a person says, “Aliens do exist and it is not the case that aliens exist,” then he is in error. His thinking is inconsistent and thus irrational. Of course, not all apparent contradictions are actually contradictions. The hypothetical individual above might clarify that he is using the term “alien” in two different senses. Perhaps he believes that extra-terrestrial aliens to not exist, but illegal aliens do. There would be no inconsistency there. A contradiction is “A” and “not-A” at the same time and in the same sense.
Outright contradictions are rarely stated as explicitly as above. Nor are they often stated back-to-back as above. If they were, they would be immediately obvious, and the debate would be over. Instead contradictions tend to be separated by time, or obscured in terminology. This can make them difficult to spot. Most forms of inconsistency are not outright contradictions. “I voted for the war before I voted against it” is not an outright contradiction, but it certainly seems inconsistent.
Another form of inconsistency is the behavioral inconsistency. This occurs when a person’s actions do not match his or her words. I often notice this in evolutionists who teach that people are just the accidental result of chemistry working over long periods of time, and really no different than an animal. But then they expect people to act morally, and to be treated respectfully, as if people had fundamental value, and are not just chemical accidents.
Perhaps you have heard someone say, “morality is relative. So you cannot go around telling other people what they can and cannot do.” But simply by making the statement, this person is “telling other people what they can and cannot do.” The statement is self-refuting.
Christians can be very inconsistent as well. If asked how they know that Christ was raised from the dead when it is not known scientifically how that could be possible, many Christians would rightly respond, “God can do as He wishes. He is not bound by laws of nature. And we know Christ was raised from the dead because it is recorded in the pages of Scripture. The text is clear.” But then again, when asked about the age of the Earth, many of those same Christians would respond, “well, the scientists say it’s billions of years old. So, maybe the days in Genesis weren’t really ‘days.’” This is very inconsistent reasoning.
Logical fallacies are marks of inconsistency. Fallacies are arguments that may sound logical on the surface, but in fact are not. Fallacies tend to be persuasive. That is why they are so common. As one example, many evolutionists try to argue their position (that all life is descended from a common ancestor) by showing examples of adaptation or variation within a kind. These are two different concepts. But since the term “evolution” can be applied to either one, evolutionists sometimes think that they have proved the former definition by giving an example of the latter. This is called the fallacy of equivocation, or the “bait-and-switch” fallacy. The meaning of the term (“evolution” in this case) was used in an inconsistent way.
A logical person is rigorously consistent, and always has a good reason for what he or she believes. If a person’s thinking is inconsistent, then we know the person cannot be (completely) right since truth will always be self-consistent. Contradictions and other less severe types of inconsistency are marks of irrationality. These indicate that the person has not been a careful thinker. Internal inconsistency within a claim necessarily means that the position is unreliable at best.
Arbitrariness is at least as bad as inconsistency. The inconsistent person is using bad reasoning. The arbitrary person is not using reasoning at all. To be arbitrary is to not have a reason. It is to have an immature, childlike way of believing in something for no good reason at all. Christians have a moral obligation to be rational: to think and behave in a way that is consistent with the character of God. And we need to challenge unbelievers to be rational as well.