1. Method for constructing a sound definition
When a definition is at issue, one technique of definition can be played against another. Typically, definitions based on common usage, on true meaning of the word, on the scientific meaning of the word can be opposed to each other.
Just as there are rules for arguments establishing a correct causal relationship, there are rules for establishing a correct definition, and therefore, critical rules for evaluating, definitions, S. Arguments establishing vs. exploiting a relationship.
These rules depend on the social or scientific fields to which the defined beings belong, and adapt to the various definition types. The more general ones are as follows.
(i) Does the definition correctly disambiguate the term according to its meanings (homonymy) and acceptances (polysemy)? S. Ambiguity.
(ii) Does the definition avoid circularity? If not, it enters a vicious circle. Words being defined with words, the whole dictionary is actually circular. As explanations or arguments in general, definitions should try to defer circularity as far as possible; that is, the definition (definiens) cannot use the word it is supposed to define (definiendum), nor a (near) synonym of the word. Nonetheless, definition through synonyms or the simple negation of an antonym does help if one of these defining words is better known than the definiendum.
(iii) Does the definition cover all the uses of the word? Does the meaning of a passage remain the same when the definiens is replaced by the definiendum? If not, the definition should be amended.
(iv) Does the definition make it possible to sort out the beings that are called by that name from those that are not? A definition might be criticized because it is too broad (it applies to heterogeneous objects or beings) or because it is too narrow (it excludes objects or beings it would be desirable to integrate). S. Definition and Argument, § 2, for the role of ostension and exemplification.
(v) Does it help? That is, does it provide sufficient information to clarify the meaning of the word, and, if need be, does it give some functional indications, or point to the scientific or specialized uses of the word?
(vi) Is the definition brief, clear, and simple? Does it use unknown, obscure or ambiguous words?
Methods and rules such as those mentioned above serve as a guide for the establishment of definitions and, consequently, for their criticism.
— The following set of available arguments in their positive form argue that the definition is sound, and in their negative form they argue that the definition is unsound.
(i) it correctly disambiguates the definiens
(ii) It avoids circularity
(iii) It covers all the uses of the word
(iv) It is neither too broad nor too narrow
(v) It is helpful
(vi) It is brief, clear, and simple
(vii) It is objective.
— These arguments are mobilized in debates on definitions or involving definitions (Schiappa 1993; 2000), that is, when there is a stasis of definition (see infra); S. True meaning of a word
— They are fundamental to the criticism of argumentations that use a definition, showing for example that the underlying definitions are poorly constructed and do not comply with such and such a rule.
3. Questions of definition
A stasis of definition, or question of definition, occurs when it appears that discourse and counter-discourse are based on incompatible definitions of the same object:
S1: — The rights of free speech and demonstration are fundamental to democracy.
S2: — What is fundamental in a democracy, is the right to have an iPhone and something to eat.
A definitional question ensues: which features are essential (central) features and which ones are accidental (peripheral) to characterize a democratic state?
Incompatible categorizations result in a question of definition:
S1: — A Syldavian Diplomat killed in an accident
S2: — Murder of a Syldavian Diplomat
Confidential information was disclosed:
S1: — A new manifestation of the malfunctioning of Syldavian Services
S2: — There are traitors in our services.
The investigator, in the role of the third party, transforms the two conflicting discourses into an argumentative question, and initiates an investigation to clarify what happened, on the basis of legal definitions:
What is murder? What is an accident?
What are the crucial differences between carelessness and betrayal?
The stasis of definition can develop as follows:
S11: — Syldavia is now a true democracy!
S21: — How dare you talk about democracy in a country that does not recognize the rights of minorities?
S12: — According to the dictionary, democracy is …; nothing in this definition mentions the rights of minorities; so, Syldavia is for sure a true democracy
S22: — This definition is poor and ideologically biased.
— The confrontation of the positions S11 and S21 produces a question of categorization.
— S12 rejects the objection of S21 by referring to the dictionary; he or she might as well have quoted the recognized conventions, international law, consensus, etc.
— S22 ratifies the stasis of definition
According to Humpty Dumpty, the best way to resolve of a stasis of definition is to appeal to power:
[Humpty Dumpty] […] — and that shows that there are three hundred and sixty-four days when you might get un-birthday presents—”
“Certainly,” said Alice.
“And only one for birthday presents, you know. There’s glory for you!”
“I don’t know what you mean by ‘glory’”, Alice said.
Humpty Dumpty smiled contemptuously. “Of course, you don’t—till I tell you. I meant ‘there’s a nice knock-down argument for you!”’
“But ‘glory’ doesn’t mean ‘a nice knock-down argument,’” Alice objected.
“When I use a word,” Humpty Dumpty said in rather a scornful tone, “it means just what I choose it to mean—neither more nor less.”
“The question is,” said Alice, “whether you can make words mean so many different things.”
“The question is,” said Humpty Dumpty, “which is to be master—that’s all.”
Alice was too much puzzled to say anything, so after a minute Humpty Dumpty began again. […]
Lewis Carroll, Through the Looking Glass, 1872 
 Quoted after Lewis Carroll, Through the Looking Glass. Chapter 6, Humpty-Dumpty. 2016. No pag. http://www.gutenberg.org/files/12/12-h/12-h.htm#link2HCH0006. (11-08-2017)