Since concepts mean everything about their potential referents, including the unknown, concepts mean things we do not know. In my using a concept, that implies I mean more than is part of my own knowledge. How is that possible?
It is possible because (and if) new existents qualify as instances of previously formed concepts. By focusing on the essential distinguishing characteristics of existents when we form a concept, we can know, in advance, that any future discoveries that differ from the previously known ones only in specific measurements or non-essential characteristics will have the same essential characteristics as the ones that led to the formation of the concept, differing only in their measurements or in non-essential characteristics. If they don't, then they're not of the same type, i.e., not subsumed by the same concept.
Ayn Rand discusses this issue at some length in Introduction to Objectivist Epistemology, Chapter 7. Here are some representative passages (from ITOE, 2nd Ed., pp. 66-69):
It is crucially important to grasp the fact that a concept is an "open-end" classification which includes the yet-to-be-discovered characterists of a given group of existents. All of man's knowledge rests on that fact.
I find the "file folder" metaphor particularly illuminating in regard to the question at hand. This discussion in ITOE also strongly points to an Objectivist solution to the age-old "problem of induction," as David Harriman's book, The Logical Leap, attempts to elaborate further.
From follow-up comments by the questioner, the question evidently was prompted by the following statement by Ayn Rand: "a concept subsumes all the characteristics of its referents, including the yet-to-be-discovered." Evidently the question amounts to asking: how can a concept subsume anything that is not already known? Doesn't something have to be known first, before we can subsume it under a concept?
I can see that Ayn Rand's statement might be puzzling if considered by itself, without relation to all the other explanation and elaboration that Ayn Rand provides. That statement is actually the conclusion of a whole paragraph in ITOE (2nd Ed., p. 66) that discusses "accumulation and transmission of mankind's knowledge," citing the example of the concept "man." Ayn Rand points out: "when roughly half the sciences (the humanities) are devoted to the study of man, the concept "man" has not changed [from that of a child or primitive savage]: it refers to the same kind of entities. What has changed and grown is the knowedge of these entities." This paragraph in ITOE also mentions that the definitions of concepts may change, and reclassifications may occur, "but these changes are made possible by and do not alter the fact that a concept subsumes all the characteristics of its referents, including the yet-to-be-discovered."
The very next paragraph introduces the "file folder" metaphor and explains it in some detail. And the whole discussion of what concepts subsume and the "file folder" metaphor begins with an introductory (topic-setting) paragraph that focuses on "the fact that a concept is an 'open-end' classification which includes the yet-to-be-discovered characteristics of a given group of existents."
All of this discussion, both before and after the statement that prompted the question, should be sufficient to resolve any puzzlement about that statement.
But others certainly needed additional clarification, also, judging by the amount of further discussion that is contained in the Appendix. Refer to "Concepts as Open-Ended" on p. 147, and especially "Meaning and Referent" on pp. 235-238. The latter discussion is extremely helpful in clarifying the relation between the meaning of a concept and the idea of "subsuming" a referent. On p. 236, Ayn Rand explains: "The meaning is the referent, but your understanding of the meaning of a concept and your knowledge about the referent aren't the same thing."
Mindy may already be familiar with these discussions in ITOE, but other readers of this website may not be. From these ITOE discussions, together with Ayn Rand's original presentation on pp. 66-69, I cannot imagine how there could still be room for confusion over what Ayn Rand meant by the idea of subsuming yet-to-be-discovered characteristics of the referents of a concept.
"Open-ended" means past, future, and not-encountered instances of particulars that correspond to a given concept. What I am asking about is more concerned with yet-to-be-discovered characteristics. Unknown characteristics can belong to instances we have actually encountered, characteristics of liver function not yet understood, for example. Those are included in the meaning of a concept, so they are part of its meaning when the concept is used. When we use a concept, we use something that means things nobody has yet discovered about the referents of that concept. In using a concept, we mean what the concept means, so our meaning includes things we do not know. Our meaning exceeds our knowledge. Does that help? p.s. I put this as an answer, because it was too long as a comment.
answered Nov 11 '10 at 16:50
Mindy Newton ♦