We routinely use a large number of very similar words when we talk about thinking: rational, rationale, rationality, irrational, rationalize, rationalization, reason, reasonable, and even superrational. We all kinda-sorta mostly generally understand the nuanced differences between these words, but since they are so very important and so often confused, it may be helpful to put them all on the table where we can clearly compare and contrast them.

Rational describes thinking that is based upon true facts and sound logic. This is the good kind of thinking. It requires that the thinker is unbiased, fact-based, sane, logical, and as objectively correct as one can be given the best information available. Note that the threshold here is quite high. It is not enough to merely follow “my own logic” to reach a conclusion, but that one follow independently valid logic and adhere to independently validated facts. One cannot merely feel they are being rational; they must in fact be objectively, measurably, demonstrably rational. A certifiably crazy person may be absolutely convinced they are perfectly rational in concluding that aliens are beaming signals into their brain, but that does not make them so.

Rational thinking implies that one meets all these requirements in a particular line of thought. A rational thinker is one who generally employs rational thinking. Often this term implies that one consciously values rational thinking as well. Although religious thinkers insist upon being shown respect as rational thinkers, it is difficult to see how their claims in any way reach the threshold of rational thinking. They seek to dilute and diminish the term so that it applies to them.

The term rationality is generally used in the context of questioning one’s rationality. That is, when we wish to make an assessment of a person’s capacity to be rational, either generally or at a given time.

Superrational is a term coined by cognitive scientist Douglas Hofstadter to describe a cooperative group behavior in game theory. However like many scientific concepts it has been incorrectly hijacked by New Age types. They invoke it to suggest that there is some intuitive mode of thought that transcends normal rational thinking – which they then invoke to justify any magical thinking they wish. They might say, for example, I believe in psychic powers because I’m a superrational thinker.

The word reason is trickier. In its basic form it is inherently neutral with regard to truth or rationality. It simply describes the cause, explanation, or justification one uses to explain their conclusion or action. But we also use it more generally to describe our rational capacity. It is in this sense that it is used for example in the “Reason Rally.” It sounds better there than would the “Rationality Rally.” The word reason also has the benefit of invoking feelings of reasonable or reasonableness.

However the connection between reason and reasonable is also a problem. Reason shares the fairly high bar with rational. But to be reasonable only requires that one be fair, moderate, and sensible. That’s why the word reason is a dangerous one to substitute for rational. Using reason as a synonym for rational can lower the bar for rationality in the minds of many people who might like to claim that their “reasonable” beliefs are rational conclusions because they are reasonable. Reasonable people can agree to disagree. Rational people cannot disagree for very long.

And that is a great segue into the biggest source of confusion amongst these terms. Just as the word reasonable dilutes the word reason, the word rationalization dilutes the word rational. Even worse, it totally reverses it!

Although it seems like they should be different forms of the same word, rationalize is almost the complete opposite of rational. To rationalize is to contrive some rationale, some apparent logic, to make the illogical appear perfectly rational. It is to “rationalize away” facts, logic, and reason. It is the process of deluding one’s self into thinking that some possibly preposterous idea is sound and credible regardless of the facts of the matter. We rationally reach scientific conclusions, but we rationalize our religious beliefs to convince ourselves that we are rational thinkers. These are not remotely equivalent.

This is insidious because once we have rationalized something, it then seems completely rational to us. Once rationalized, we become certain that our thinking is perfectly sound and reasonable. And we have evolved to be incredibly good at rationalizing. From the evolutionary perspective it was evidently far more important that we feel certainty in the face of ambiguity or the unknown; that we reach harmonious consensus in a delusion, than that we know the real facts of the world. There is also evidence that belief served a benefit of requiring less energy consumption as well (see here). But belief is no longer a beneficial or even harmless adaptation in our modern world.

Despite the fact that it no longer serves us well, we as a species remain incredibly good at rationalizing. Clinically delusional people are often completely certain that their delusions are perfectly rational. But this isn’t just an affliction of the insane. Rationalization is our normal human brain function that we are all susceptible to. Once rationalized, we normally continue to believe any ridiculous belief without reevaluation. We don’t need to be beyond the threshold of insanity to hold some insane rationalizations.

The lesson then is to be very skeptical when anyone insists that their conclusions are rational – even when it is ourselves. Few of us can distinguish between our own truly rational positions and completely rationalized ones. Fortunately science gives us methods to help us assess whether our conclusions are fact-based and soundly logical.

Likewise, we don’t need to train our young thinkers to rationalize problems, as they are innately quite adept at that already. Education in debate, law, marketing, sales, religion and many other fields mostly enhance our innate ability to create any argument that convinces others – to rationalize. We need far more training in science and skeptical thinking so that we can  better judge whether the rationalizations that impact our lives are truly rational.