I’m not sure what distinction you are making here, but the relevant point is that you are telling me that in order to derive or discover a concept, we must first find the referents.

That's the only distinction I was trying to make, as well.  The word 'derive' suggests a logical derivation, as though once you have some, others logically follow.  However, the reality is that concepts are empirically formed.  And yes, every concept must have referents.  It's not so much that you "find" the referents in the sense that you're actively seeking them out, since that would suggest that you know what you are looking for already.  The existents which will be the referents are available to you as knowledge, and you begin the concept-formation process by noting similarities and differences.

But in order to find those referents we must surely have an idea of what we are looking for, which in turn requires us to understand what is meant by the relevant term, otherwise we would not know what we are trying to identify. But that means we must presuppose the term we are trying to discover!

You don't have to have the concept in advance in order to form it.  The examples I've given you describe the formation process of concepts which we both know, since I figured that the point would be better illuminated.  If I were to do this with a concept I'm not sure you know (like a topology), I may run into the problem that you don't know what the referents are, defeating my attempt.

You are right that in teaching someone a term that they have no reason to naturally form on their own, you must begin with a definition describing what the referents of the concept are.  Then, depending on how bright the student is or the difficulty of the subject matter, you may need to give some examples of the notion you defined so as to give the students explicit referents.  Without these referents, the term is meaningless, as far as the student is concerned.  However, for every concept we have, someone had to arrive at it naturally, i.e., without being taught the definition first.

Which brings us to “definite”. Using an everyday example such as “table”, and assuming the blank slate, how you would derive the concept “definite”, without presupposing the term?

Ah, now here you touch on a different question: "How does a child learn anything if it is assumed that they are born blank slate?"  Rand addresses this in the epistemology workshop under the heading "Abstraction as Volitional" (IOE, 2nd ed., pp. 150-2)  If you own a copy of IOE, you should give it a look, but I can paraphrase her argument on the matter here.

Rand says that even though a child is born blank slate, the child still has the "will to observe" his surroundings via volition.  In so doing, he forms the first first-level concepts he ever will, and from there the process of abstraction upon abstraction begins.

In any case, given that you know of two red objects, two green objects, and Sartre's term "noughting nought" (or any equally vague term of your choosing), you can validly form the concept "definite."  What else do you want me to do?

Nate

Well, here I agree of course. This is just what I mean about concepts being put to good use - as rough general ideas, subject to radical correction as our knowledge grows. See how useful they are, even when they are even demonstrably false in some key respects! (Likewise, no doubt our current beliefs about electromagnetic phenomena will be found to be false in important ways in the future)

But where this goes wrong is if we try and establish concepts too precisely in advance - to pretend that we have to have perfectly true concepts before we can have a meaningful debate, or before our knowledge can grow. This is the same as the mistaken belief that we can only move to the exact truth *from* the exact truth! (in fact, we always start *in error* of a greater or lesser degree, and move closer to the truth) If we needed perfect concepts to begin with, well, we wouldn't even be able to *start*, let alone move from relativity to gravity!

So, as your example clearly shows, we shouldn't worry too much about concepts, nor as a consequence the words that describe them! And this is my point.

Nate writes (to Brendan)
>By my last post, the concepts "red" and "green" are subsumed under "definite", since I can tell the difference between red and not red, green and not green.

So, by this method, I can say I "definitely" know how much money is in my bank account just because it's *not* $1 million dollars!

As I remarked earlier, this is rather like firing a shot at the side of a barn at point-blank range, then declaring yourself an expert marksman because, well, you didn't hit the "not-barns" ie: the tree, or the fence, the passing car..!

But as I say, there is little point arguing over words. If that's what you want to call "perfectly definite" or "absolutely precise" or whatever, that's fine by me. To non-Objectivists, however, it seems rather vague indeed...;-)

Personally, I find many *Objectivists* do not seem to have a good first-hand grasp of the IOE. For example, in this debate neither Rick nor Nate had realised Rand *had* made a reasonably clear statement on the status of singular items as a form of concept! It took a non-Objectivist (ie: me) to point it out to them.

This isn't really their fault however, nor, sadly, a demonstration of the genius of my public education...;-). It's just that in addition to being a particularly poorly written book, it's unlikely to be very closely examined by people who are already convinced of its truth.

Well I am very much enjoying the challenge of discussing this with you. My belief is that people with quite different philosophical outlooks can and indeed *must* be able to discuss things like this. To deny that this is possible - to break off discussion, as so often happens, because of alleged differences over "fundamentals" - is a capital-F Fundamentalist error. After all, if you're not discussing fundamentals, you're discussing trivia...;-)

As we all must - this is the essence of the critical approach.

I think the problem is not so much that I don't understand the IOE, as Rick suggests, but that the IOE itself is incoherent.

Concepts are, according to Objectivism:
1) Neither true nor false
2) Both "open-ended" and "perfectly definite"
3) Both changing and unchanging
4) Neither complete nor incomplete