The Definition Of Definitions

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The sentence “all cats are black” is evidently untrue even if only one cat in the whole universe were to be white. Thus, the property “being black” cannot form a part of the definition of a cat. The lesson to be learnt is that definitions must be universal. They must apply to all the members of a defined set (the set of “all cats” in our example).

Let us try to define a chair. In doing so we are trying to capture the essence of being a chair, its “chairness”. It is chairness that is defined – not this or that specific chair. We want to be able to identify chairness whenever and wherever we come across it. But chairness cannot be captured without somehow tackling and including the uses of a chair – what is it made for, what does it do or help to do. In other words, a definition must include an operative part, a function. In many cases the function of the Definiendum (the term defined) constitutes its meaning. The function of a vinyl record is its meaning. It has no meaning outside its function. The Definiens (the expression supplying the definition) of a vinyl record both encompasses and consists of its function or use.

Yet, can a vinyl record be defined in vacuum, without incorporating the record player in the definiens? After all, a vinyl record is an object containing audio information decoded by a record player. Without the “record player” bit, the definiens becomes ambiguous. It can fit an audio cassette, or a compact disc. So, the context is essential. A good definition includes a context, which serves to alleviate ambiguity.

Ostensibly, the more details provided in the definition – the less ambiguous it becomes. But this is not true. Actually, the more details provided the more prone is the definition to be ambiguous. A definition must strive to be both minimal and aesthetic. In this sense it is much like a scientific theory. It talks about the match or the correlation between language and reality. Reality is parsimonious and to reflect it, definitions must be as parsimonious as it is.

Let us summarize the characteristics of a good definition and then apply them and try to define a few very mundane terms.

First, a definition must reveal the meaning of the term or concept defined.