Saying a definition is a description is a total dumbing down. I don't know why they don't teach this stuff in grade school anymore... they should.
A definition must identify the nature of the units, i.e., the essential characteristics without which the units would not be the kind of existents they are.
And
The rules of correct definition are derived from the process of concept-formation. The units of a concept were differentiated—by means of a distinguishing characteristic(s)—from other existents possessing a commensurable characteristic, a Conceptual Common Denominator. A definition follows the same principle: it specifies the distinguishing characteristic(s) of the units, and indicates the category of existents from which they were differentiated.
The distinguishing characteristic(s) of the units becomes the differentia of the concept’s definition; the existents possessing a Conceptual Common Denominator become the genus.
Thus a definition complies with the two essential functions of consciousness: differentiation and integration. The differentia isolates the units of a concept from all other existents; the genus indicates their connection to a wider group of existents.
For instance, in the definition of table (“An item of furniture, consisting of a flat, level surface and supports, intended to support other, smaller objects”), the specified shape is the differentia, which distinguishes tables from the other entities belonging to the same genus: furniture. In the definition of man (“A rational animal”), “rational” is the differentia, “animal” is the genus.
No. I see that they also don't teach the history of continental philosophy in grade school. The term that you are conflating with the word "definition" is most closely related to the philosophical term "essence." Essence is the property which give things their identity -- an object without its essence loses its concrete identity. When Socrates attempts to find the essence of virtue, he does not seek to describe the things which we believe are virtuous (because complete correctness could simply be found here by enumeration), but to find the subject whose identity we are describing using the term "virtue."
Definition, however, is a descriptive, not proscriptive term. Succinctly, the definition of a term is whatever a broad consensus "agree" upon. Dictionaries serve to help identify that consensus, although they are not completely authoritative. The definition of a word may not coincide with its essence in any way -- for example, the phrase "to beg the question" has two primary definitions. The first and newer definition is equivalent to "to ask the question." The second and older definition is to assume the conclusion within the question itself. Together these definitions do not elucidate the "essence" (or "distinguishing characteristic", in Ayn Rand's primitive terminology) because they are wholly unrelated to each other. Instead, they're simply descriptions of the common modes in which English-speaking society uses the phrase "beg the question."
The best example is your definition of the word definition. The word "definition" does not have any intrinsic meaning -- only that which we place on it. Moreover, the meaning can vary between subsets of the broader population -- your use of the word definition in no way coincides with my use of the term in formal mathematics. This doesn't mean that you can't disagree with a given definition for a word, only that you're insistence that you're correct or even that your definition has some objectively superior qualification makes your use of the word the "correct" one.
Needless to say, I disagree with you on this topic. I can't make a better argument than the book from which I pulled those quotations, so I'll direct people who are interested there.
I wasn't hunting down your posts, was just continuing the thread.
And I don't think I was being arbitrary. When challenged on your point you merely pointed to the quotes you had made and told people to read the book, which to me is pure dogma.
So admittedly I got a bit snarky. Although I was also attempting to be a bit self critical, which was why I referenced that quotation.
I honestly got reminded of the quote from Futurama.
And I honestly don't take Ayn Rand as a definitive resource on much beyond her own ego. She claimed that her philosophy was unique, other than a sole debt to Aristotle. Aristotle of all people. The guy who can't even count the legs of a fly and who thinks that menstruating women cloud mirrors if they look in them. So sorry if I stoop to ridicule if you worship her turgid prose, but really.
[edit] Also - as to her definition of table that you gave, well it could just as easily be describing a shelf. And the idea of the definition of table being some absolute thing based on shape is preposterous. I do wish these philosophers would have a chat with some designers before waffling on about platonic forms of household objects. A table is defined by usage, expectation and personal perception. In weightless environments, the concept of table could easily be a clear, easily accessible floating box kept in the middle of a spacecraft's living space, for instance.
You can't judge Ayn Rand (well, anyone--and that's my real point) by a mistaken attack on someone else (Aristotle). That's worse than judging her by a cartoon. Again, it's not an honest approach.
So sorry if I stoop to ridicule if you worship her turgid prose, but really
In case you actually think I approach ideas in a dishonest, religious way (hence, "worship")--I don't. This is just a stupid comment.
And the idea of the definition of table being some absolute thing based on shape is preposterous
This is a misunderstanding of the idea being presented. But anyway, you couldn't get a complete understanding without reading the original source (it's from a book), so speculating on it here is probably pointless.
I can judge Ayn Rand's philosophy partly on that of Aristotle given that she claimed to be a philosopher who owed nothing to anyone else in her philosophy other than Aristotle. Which I personally think is a completely ludicrous and frankly egotistical thing for anyone to try and claim.
So how am I being dishonest?
Also, how have I misunderstood the idea being presented here;
"For instance, in the definition of table (“An item of furniture, consisting of a flat, level surface and supports, intended to support other, smaller objects”), the specified shape is the differentia, which distinguishes tables from the other entities belonging to the same genus: furniture."
Now admittedly, the book may expound upon this and create a completely different interpretation based on the overall context, but given that you presented me with this excerpt and claimed it as a reasonable argument, you will forgive me for dealing with only the words that were in front of me at the time.
but given that you presented me with this excerpt and claimed it as a reasonable argument
I didn't claim it as a reasonable argument. I don't think it's very useful out of context. Just wanted to illustrate genus and differentia.
So how am I being dishonest?
You're being dishonest because you're just indulging your emotional whims by "judging" things on completely irrational criteria, instead of actually examining the ideas.
Is funny, I'd say you were being irrational due to an emotional attachment to Ayn Rands work.
That was my judgement when you used her lexicon as the ultimate arbiter of the definition of 'definition' and then just told people to read it when challenged on this position.
A definition must identify the nature of the units, i.e., the essential characteristics without which the units would not be the kind of existents they are.
And
The rules of correct definition are derived from the process of concept-formation. The units of a concept were differentiated—by means of a distinguishing characteristic(s)—from other existents possessing a commensurable characteristic, a Conceptual Common Denominator. A definition follows the same principle: it specifies the distinguishing characteristic(s) of the units, and indicates the category of existents from which they were differentiated.
The distinguishing characteristic(s) of the units becomes the differentia of the concept’s definition; the existents possessing a Conceptual Common Denominator become the genus.
Thus a definition complies with the two essential functions of consciousness: differentiation and integration. The differentia isolates the units of a concept from all other existents; the genus indicates their connection to a wider group of existents.
For instance, in the definition of table (“An item of furniture, consisting of a flat, level surface and supports, intended to support other, smaller objects”), the specified shape is the differentia, which distinguishes tables from the other entities belonging to the same genus: furniture. In the definition of man (“A rational animal”), “rational” is the differentia, “animal” is the genus.
Both are from http://aynrandlexicon.com/lexicon/definitions.html