Certainly the most interesting tool that science employs in its perpetual pursuit of knowledge is the scientist, with his enthusiasms, egoisms, and prejudices, his inevitable unconscious attitudinal orientation in the consensus of contemporary opinion, which we call the Zeitgeist. One wonders what science would be like if automation could take over completely. Are there mechanical equivalents for jealousy and pride and pigheadedness and insight, and those other interacting personal forces that contribute to contemporary truth in the scientific field?

Fechner never tried to found psychophysics or a new experimental psychology. He was, in his own estimation in those last forty-five years of his life, a philosopher, fighting what he regarded as the crass materialism of his day, the Nachtansicht or “night view,” as he called it, and promoting the faith that mind and soul are the ultimates of reality, the Tagesansicht or “day view.” This favoring of the clear philosophical vision in the day view as opposed to the materialistic darkness of the night view is Fechner’s panpsychism, a faith that seems mystical to most modern scientists, partly because the German word Seele does not distinguish between mind and soul, between that which compares the sensory intensities of two lifted weights and whatever it is that persists after the body’s death.

Fechner’s work [12] was motivated by an interest in the mind-body problem concentrating particularly upon the question, “What is the relationship between the measurable characteristics of the physical stimulation and the subjective characteristics of the sensations produced?” Some of Fechner’s work was devoted to experiments in areas where the physical measurements that can be made on the object are not functionally related to the psychological characteristics.

The appearance of a statistical paper in a symposium honoring the founding of psychophysies was surely to have been expected. These two disciplines had their modern beginnings in about the same period of time and the well-known founders of each made at least some contributions in the other. Karl Pearson’s research on the personal equation is still a good example of painstaking psychophysical experimentation. Indeed much of his statistical reputation rests on techniques he developed to analyze this data. Fifty years ago Urban published, in a psychological journal, the final form of the Müller-Urban weights. Twenty years later biologists rediscovered Urban’s weights and now use them routinely. Spearman, too, contributed to both fields.

The occasion of a symposium to honor Fechner on the centennial of the publication of his Elemente der Psychophysik (1] has provided an excuse to review the Fechnerian legacy and to ask what perversity in the nature of science or the Zeitgeist has made it possible for Fechner’s concept of error to persist for a hundred years and grow famous. The central feature of this legacy is the notion that the jnd (just noticeable difference) can serve as a unit for the measurement of sensation. Since the jnd is really a measure of the uncertainty, dispersion, or variability among a set of judgments, this proposition makes residual “noise” the yardstick of sensory magnitude–a notion as curious as it seems improbable. Why did this conception survive its inventor, and why did it become, under Thurstone's expert guidance, the foundation of psychological measurement applied to subjective values and attitudes? Thurstone’s Case V in which he assumes equal discriminal dispersions (equal subjective variabilities) matches in effect the Fechnerian assumption that all jnds are subjectively equal.

We are gathered today to commemorate the completion of the first quarter of a century of the Society’s history, and I consider it no small honor to have been selected to address this distinguished group on this memorable occasion. When Dr. Charles Wrigley, Chairman of the Program Committee, extended the invitation, he expressed the hope that I would review the history of the formation of the Society and discuss something of its achievements to date. Today I shall only highlight the early history of the organization, since in my Presidential Address in September 1941 a rather full history was presented.

Several types of new developments in statistical behavior theory deserve attention: (i) attempts at relatively direct empirical tests of basic axioms; (ii) the application of models that survive these tests for purposes of data reduction and analysis; (iii) the extension of extant models, or elaborations of them, to new empirical problems; and (iv) the introduction of new models based primarily on abstract mathematical considerations. The last two of these “new developments” have been well represented in recent books [3, 11]; the first two will be illustrated in the following sections.

Twenty-five years ago, when the Psychometric Society was formed, the new developments that were then shaping the course of psychometric research were subjective scaling and factor analysis. Today, a development that seems destined to influence psychometric research in the next twenty-five years is the simulation of cognitive processes on high-speed digital computers. So far, of course, there has been more talk about the potential utility of computers in psychology than there has been accomplishment; nevertheless, what achievements have been made seem to me to imply a bright future.

About 27 years ago, a small group of students met with Professor Thurstone in Chicago to discuss methods of encouraging quantitative work in psychology. The initial group that was concerned about the slow rate of development of quantitative work in psychology included Jack Dunlap, Al Kurtz, Marion Richardson, John Stalnaker, G. Frederic Kuder, and Paul Horst. They had discussed the problem, had been helped a bit by Donald Paterson, and had decided that possibly if a magazine were set up to publish quantitative psychological material this would facilitate the development of the field. Persons who did good quantitative work, either theoretical or experimental, would thus have a forum where it would be accepted because it was high quality quantitative work, rather than being rejected because it was quantitative and hence “not of too great interest” to the readers.

When writing this paper as well as during our commemorative luncheon, I could not help going back in memory to two experiences. One of these occurred during the fall semester of 1935 while I was visiting professor at Northwestern University and took advantage of the opportunity and had the rare privilege of attending Thurstone’s seminar. The atmosphere at the University of Chicago at that time clearly reflected the birth and early infancy of both the Psychometric Society and its Journal Psychometrika.

The other experience comes back in the form of an image of our first annual dinner in the Inn at Dartmouth College in September 1936. The banquet had an unexpectedly large and enthusiastic attendance. Thurstone provided one of his memorable addresses, which was later published in Science, entitled “Psychology as a quantitative rational science” [35]. The address is well worth rereading.

I might spend the time alloted to me in declaiming the merits of quantitative psychology and what it has done for the progress of psychology in general. But in this group I shall take our substantial contribution for granted and try instead to help measurement psychologists look at themselves and their own progress and some of their own problems.