4.6 Disputes about definitions in logics

At one time, there was a principle: “There is no argument about definitions”. Sometimes he was expressed a little differently: "Arguing about the words of the ns." The NS is quite clear where this principle came from and on what exactly it was based, but many people repeated it as a matter of course.

How true is he? The answer to this question is not difficult: the opinion that it is unreasonable or even pointless to argue about definitions is clearly wrong. It is inconsistent with the general concept of definitions and their tasks in everyday life and in scientific research. This opinion also contradicts the obvious fact that definitions have always been argued and continue to argue now. However, in these disputes there is one subtlety that is important to understand correctly.

The debate about the definitions of different types - real and nominal - is fundamentally different from each other.

The real definition is the description of some collection of objects. He is required to reveal the essence of the objects in question and thereby unambiguously distinguish them from all other things. Checking the correctness of such a definition is comparing it with the described area. An adequate description is true, a description that does not correspond to the real situation is false.

Disputes over real definitions are common disputes about the truth of our statements about reality.

The situation is different with nominal definitions. They do not describe something, but require it to be realized. Therefore, the dispute here will not be about the truth of some description, but about the expediency, effectiveness, legitimacy, etc. put forward requirements.

Suppose someone defines a hippopotamus as a "predatory artiodal mammal of the suborder of non-ruminants." We have the right to argue that such a definition is incorrect, because it is false. It is not true: hippos are not predators, but herbivores.

But suppose someone says that he will henceforth call all the representatives of the order of reptiles, including gavials, alligators, and real crocodiles, behemoths. It is clear that in this case it cannot be said that the definition is false. A person who introduces a new word does not describe anything, but only requires, from himself or from others, that the objects in question be called this, and not another word.

But the dispute is possible and appropriate here. Gavialov, alligators and real crocodiles are usually called crocodiles. What is the point of changing this well-established name in the name of "hippopotamus", especially since the latter was fixed for completely different animals? What is the expediency of such a replacement? What is the use of it? Obviously none. Worse, the inevitable confusion, if renamed, will cause direct harm. Our objections thus boil down to the fact that the proposal — or even the requirement — to rename crocodiles as hippos is inexpedient and inefficient. In this case, it is better to leave everything as it was.

So, the definition of any kind in principle can be a subject of controversy or discussion. But arguing about definitions-requirements is needed differently than about definitions-descriptions.