The Name Game
Too often in science we operate under the principle that "to name it is to tame it", or so we think. One of the easiest mistakes, even among working scientists, is to believe that labeling something has somehow or another added to an explanation or understanding of it. Worse than that we use it all the time when we are teaching, leading students to believe that a phenomenon that is named is a phenomenon that is known, and that to know the name is to know the phenomenon. It's what I, and others, have called the nominal fallacy. In biology especially, we have labels for everything — from molecules to anatomical parts, to physiological functions, to organisms, to ideas or hypotheses. The nominal fallacy is the error of believing that the label carries explanatory information.
An instance of the nominal fallacy is most easily seen when the meaning or importance of a term or concept shrinks with knowledge. One example of this would be the word "instinct". Instinct refers to a set of behaviors whose actual cause we don't know or simply don't understand or have access to; and therefore we call them instinctual, inborn, innate. Often this is the end of the exploration of these behaviors, they are the nature part of the nature-nurture argument (a term that itself is likely a product of the nominal fallacy) and therefore can't be broken down or reduced any further. But experience has shown that this is rarely the truth. In one of the great examples of this, it was for quite some time thought that when chickens hatched and they immediately began pecking the ground for food, this behavior must have been instinctive. In the 1920s a Chinese researcher named Zing-Yang Kuo made a remarkable set of observations on the developing chick egg that overturned this idea — and many similar ones. Using a technique of elegant simplicity he found that rubbing heated Vaseline on a chicken egg caused it to become transparent enough to see the embryo inside without disturbing it. In this way he was able to make detailed observations of the development of the embryo from fertilization to hatching. One of his observations was that, in order for the growing embryo to fit properly in the egg, the neck is bent over the chest of the body in such a way that the head rests upon the chest just where the developing heart is encased. As the heart begins beating the head of the chicken is moved in an up-and-down manner that precisely mimics the movement that will be used later for pecking the ground. Thus the "innate" pecking behavior that the chicken appears to know miraculously upon birth has, in fact, been practiced for more than a week within the egg.
In medicine as well, physicians often find technical terms that lead patients to believe that more is known about pathology than may actually be the case. In Parkinson's patients we notice that they have an altered gait and in general that their movement's are slower. Physicians call this "bradykinesia", but it doesn't really tell you anymore than simply saying "they move slower".
Why do they move slower, what is the pathology and what is the mechanism for this slowed movement - these are the deeper questions hidden by the simple statement that "a cardinal symptom of Parkinson's is bradykinesia", satisfying though it might be to say the word to a patient's family.
In science the one critical issue is to be able to distinguish between what we know and what we don't know. This is often difficult enough as things that seem known, sometimes become unknown or at least more ambiguous. When is it time to quit doing an experiment because we now know something, when is it time to stop spending money and resources on a particular line of investigation because the facts are known? This line between the known and the unknown is already difficult enough to define, but the nominal fallacy often obscures it needlessly. Even words like gravity, which seems so well-settled, may lend more of an aura to the idea than it deserves. After all, the apparently very well settled ideas of Newtonian gravity were almost completely undone after 400 years by Einstein's General Relativity. And still today physicists do not have a clear understanding of what gravity is or where it comes from, even though it's effects can be described quite accurately.
Another facet of the nominal fallacy is the danger of using common words and giving them a scientific meaning. This has the often disastrous effect of leading an unwary public down a path of misunderstanding. Words like 'theory', 'law', 'force', do not mean in common discourse what they mean to a scientist. 'Success' in Darwinian evolution is not the same 'success' as taught by Dale Carnegie. Force to a physicist has a meaning quite different from that used in political discourse. The worst of these though may be "theory" and "law" which are almost polar opposites — theory being a strong idea in science while vague in common discourse, and law being a much more muscular social than scientific concept. These differences lead to sometimes serious misunderstandings between scientists and the public who supports their work.
Of course language is critical and we must have names for things to talk about them. But the power of language to direct thought should never be taken lightly and the dangers of the name game deserve our respect.