You mentioned that you once asked an Objectivist if he thought people actually use measurement omission to form their concepts. In your recollection, he replied that he didn't really care how people actually form concepts, since anyway, Rand had shown the right way to do it.
I suspect you were hearing a garbled version of a conclusion I had reached in my essay "Capturing Concepts." That essay appeared in the first issue of my philosophy journal Objectivity (1990 1(1):13-41). I know you are familiar with this journal because I published your essay "On Newtonian Relative Space" in it (1993 1(6):37-53).
That premier issue of Objectivity was widely circulated among Objectivist types. Preceding the passage in "Capturing Concepts" that was to become somewhat famous, I had observed that logic is not a method we are always bound to employ (correctly) in our reasoning. I mentioned John Macnamara's conception of logic as a theory of competence in reasoning. Then, I wrote:
Similarly, Rand's theory of concepts might best be seen as a theory of competence in conceptual function. Her model for concept formation should perhaps not be taken as a model of how we must conceive things, but of how we, as adults, can conceive them when we want to clarify our concepts and understanding. Rand supposed that in rendering exact the meaning of one's concepts one is retracing to some extent the logical steps by which they were formed (IOE 51, 41). Perhaps we need only trace logical steps by which they could have been formed. I suggest that the model process of concept formation may not be always our way of generating or regenerating conceptual thought, and yet it may be our way of validating those thoughts. (And in validation do we not reform?). (p.34)
In this 1990 article, I assimilated the latest research on categorical perception and on preschoolers' conceptual development. It was on those bases that I concluded that Rand's theory of concept formation by measurement omission is not the child's earliest method of concept formation; that, rather, measurement omission is an advanced and ideal method. The research I assimilated in this article included results from Anne Treisman, Jean Mandler, John Macnamara, Linda Smith, Frank Keil, and many others.
Mr. Parille, if you or anyone else reading this post would like to have a copy of my "Capturing Concepts," just send me a note at email@example.com.
One subscriber to Objectivity was Allan Gotthelf, and he wrote me a thoughtful letter concerning "Capturing Concepts." He found the article competent and interesting. He noted that I was obviously very familiar with the related psychological research and that I handle the Objectivist material well.
He entered a reservation, however, which I think is good to keep in mind in this sort of undertaking. In my "Capturing Concepts" (and in the child-development section of my more recent article "Universals and Measurement"), I integrate with manifest ease the results of psychological research by a wide range of researchers, who have a variety of sometimes conflicting frameworks that may structure their evidence and its interpretation. In my articles, I don't get to say very much about those variations in research frameworks or the nuances of their theoretical concepts. Think of the term competence. Is it used by Kagan, by Macnamara, and by us in the same way? To corroborate my judgment about the significance of the research I bring to bear on Rand's theory, the reader may want to dig into the source references I supply.
By the way, Fred, Gotthelf remembers me and Objectivity to this day. Although I had attended some sessions of the Ayn Rand Society over the years, Prof. Gotthelf and I had never really met. So when I spotted him at PSA in Austin this past November, I went over and introduced myself. He immediately turned to the young graduate student from Pitt with whom he had been speaking and said: "This is Stephen Boydstun. He was the editor of Objectivity. He comes from a scientific and technical background." It is so nice to hear that someone remembers you were here and what you were about.
I clearly remember---and appreciated---your participation in the discussions of my paper "Universals and Measurement" at the Advanced Seminar of TOC in 2003. As you will recall, the major section of that paper is on the logicomathematical analysis of concepts under Rand's formula; the shorter section is on theory of the formation of concepts. In the analysis section, the phrases "formation of concepts" and "concept formation" are never used. They are inappropriate for work in that new grand garden growing out of Rand's theory.
As I hope you know, Fred, my essay "Universals and Measurement" was published last spring in The Journal of Ayn Rand Studies (V5N2). That issue of JARS has been sold out, but if anyone would like to have a free electronic version of "Universals and Measurement," just send me a note at firstname.lastname@example.org.