What is definition? This is a question hard to answer. This requires the definition of definitions. You must know what a definition is before defining definitions. To get out of this circulation, let’s first follow the traditional definition and then examine the validity of it.
1. The traditional definition
Traditionally a definition of a concept is to decide the extension and connotation of it with the definiens genus and specific difference. For example, a definition, "Men are rational animals", defines the human species in terms of a genus, animal, and a specific difference, rational.
A definition is a kind of explanation, but unlike other explanations, it is tautological and analytic. So, the reverse proposition, "Rational animals are men" is also true. This means you can analyze the definiens of definitions into the genus, "explanation" and the specific difference, "analyticity".
2. The problems of the hierarchy model
Human species is a species of the animal genus and the animal is in turn a species of the living thing genus. The genus/species differentiation is thus relative. Generally speaking, the wider the extension is, the narrower the connotation is. When you locate the universe upward and individuals downward, the genus/species differentiation forms a hierarchy. According to the Porphyry’s Tree, the most universal genus concept that ranks on top of the tree is substance.
Can we define the essence of all concepts by ranking them in the genus/species hierarchy? Let’s replace the subject/predicate relation with the subject/role relation. We are apt to define our titles in reference to the organization as a genus and the position there as a specific difference. But maybe you don’t want to regard such a pair of genus and specific difference as your essence. You should have more possibilities.
The information revolution has decentralized the top-down hierarchy to the interactive network. We need to deconstruct the genus/species hierarchy so as to adjust the way to define concepts to the network era.
3. From hierarchy to network
First, let’s doubt the difference between genus and specific difference. The genus is generally supposed to include the specific difference extensionally. So, in the case of "rational animals" the extension of animals must include that of rational beings. Really? If you believe in a rational computer or the rational God, the extension of rational beings protrudes from that of animals. You can consider "rational beings" to be a genus and "animals" to be a specific difference. Making the difference between genus and specific difference relative enables you to adopt the horizontal connection model instead of the vertical integration model.
The trans-directory net surfing on the web via hyperlinks is based on the horizontal connection model. As the directory tree symbolizes, the file management by computer in the pre-network era was based on the vertical integration model. Although the directory tree is useful and manageable, you may find that a file is more similar to other files in other directories than another file in the same directory. Hyperlinks can solve such inconvenience.
Not only two components of definiens, genus and specific difference, have no vertical difference, but also the definiendum has various candidates of definiens horizontally in the network. For example, besides rational animals, the definiens of men can be the limited beings that often waver in their minds or the emotional animals that often weep or laugh and so on. Some might consider these other predicates to be more essential to men. Likewise, a woman is not only an employee of a corporation, but also a mother, a Themestreamer and so on. Some might consider these other roles to be more essential to her.
Senses of words are in the differentiated interactive network, where a sense is defined by neighboring senses and defines them reflectively at the same time. It depends on men, which neighbors which, and because of this difference, men are in the differentiated interactive, namely social network on the meta-level. That’s why words can always be defined otherwise than it is, though the definition should be analytic.
I defined the definition as an analytic explanation of concepts. But here is a dilemma. If a definition is analytic and tautological, it is unworthy of explanation. If a definition is worth explaining, it cannot be analytic. It is the social network that solves this dilemma. For those who defined a word the definition is obvious and analytic. But in the social network, words can always be defined otherwise than it is. So, they need to explain their definitions to others.