Elements of Psychophysics, Vol. I

The empirical law, which forms the main foundation of the science of mental measurement German: psychische Masslehre; the study of quantifying internal experiences, has long since been established by various researchers in different fields. It has been expressed and experimentally proven with a relative degree of generality, notably by E. H. Weber Ernst Heinrich Weber (1795–1878) was a German physician whose research into the "just noticeable difference" in touch and weight perception became the foundation for Fechner's work, whom I would broadly call the father of psychophysics. On the other hand, the mathematical function—which represents the most general and important case of applying our measurement principle—was also established long ago on this law for specific cases belonging to psychophysics. This was done by various mathematicians, physicists, and philosophers, such as Bernoulli (Laplace, Poisson), Euler (Herbart, Drobisch), and Steinheil (Pogson), and has been reproduced or accepted by other researchers. Although all of this did not occur from the perspective of a mental measure German: psychisches Mass, and without attracting much attention until now, it will easily become clear—once the principle of this measurement is explained later in Chapter 7—that it was already contained in the function established by those researchers.

Accordingly, our mental measurement is indeed a generalization from one side and, from another side, the clear statement of the significance of what already existed as a mental measure. Referring to this history should help reduce the mistrust that the announcement of such a measurement might initially provoke. The problem of this measurement is indeed not the problem of the squaring of the circle A classic geometric problem that was proven impossible to solve; Fechner uses it as a metaphor for a "fool's errand" or a perpetual motion machine original: "Perpetuum mobile"; a hypothetical machine that works forever without an energy source, which violates the laws of physics; rather, it has effectively been solved by researchers whose names are a guarantee of the validity of the solution.

After having reflected upon these merits of earlier researchers regarding the main subject of this writing, I would neglect a primary duty if I did not also acknowledge the equally essential support and promotion that I myself received from my...