Gustav Theodor Fechner (/ˈfɛxnər/;German:[ˈfɛçnɐ]; 19 April 1801 – 18 November 1887)[1] was a Germanphysicist,philosopher, and experimentalpsychologist. A pioneer inexperimental psychology and founder ofpsychophysics (techniques for measuring themind), he inspired many 20th-century scientists and philosophers. He is also credited with demonstrating the non-linear relationship between psychologicalsensation and the physical intensity of a stimulus via the formula:, which became known as theWeber–Fechner law.[2][3]
Fechner was born atGroß Särchen, nearMuskau, inLower Lusatia, where his father, a maternal uncle, and his paternal grandfather were pastors. His mother, Johanna Dorothea Fechner (b. 1774), née Fischer, also came from a religious family. Some biographers consider, that despite these religious influences, Fechner became an atheist in later life,[4] while the others says that Fechner had his own religious system as a synthesis of Christianity and paganism.[5]
Fechner's father, Samuel Traugott Fischer Fechner (1765-1806) was free-thinking in many ways, for example by having his children bevaccinated, teaching them Latin, and being a passionate grower of fruit.[4] He died unexpectedly in 1806, leaving the family destitute.[6] Fechner had an elder brother,Eduard Clemens Fechner (1799-1861) and three younger sisters: Emilie, Clementine, and Mathilde. Fechner and his brother were then raised for a few years by his maternal uncle—the pastor, before being reunited with his mother and sisters inDresden.[4]
Fechner was educated first atSorau (nowŻary in WesternPoland).
In 1834 he was appointed professor ofphysics at Leipzig. But in 1839, he injured his eyes in the research on afterimages by gazing at the Sun through colored glasses,[9] while studying the phenomena of color andvision, and, after much suffering, resigned. Subsequently, recovering, he turned to the study of themind and its relations with the body, giving public lectures on the subjects dealt with in his books.[10] Whilst lying in bed, Fechner had an insight into the relationship between mental sensations and material sensations. This insight proved to be significant in the development of psychology as there was now a quantitative relationship between the mental and physical worlds.[11]
Fechner published chemical and physical papers, and translated chemical works byJean-Baptiste Biot andLouis Jacques Thénard fromFrench. He also wrote several poems and humorous pieces, such as theVergleichende Anatomie der Engel (1825), written under the pseudonym of"Dr. Mises."[10]
Fechner's epoch-making work was hisElemente der Psychophysik (1860). He started from themonistic thought that bodily facts and conscious facts, though not reducible one to the other, are different sides of one reality. His originality lies in trying to discover an exact mathematical relation between them. The most famous outcome of his inquiries is the law known asFechner's Law, which may be expressed as follows:[10]
"In order that the intensity of a sensation may increase in arithmetical progression, the stimulus must increase in geometrical progression."
The law has been found to be immensely useful, but to fail for very faint and for very strong sensations. Within its useful range, Fechner's law is that sensation is a logarithmic function of physical intensity.S. S. Stevens pointed out that such a law does not account for the fact that perceived relationships among stimuli (e.g., papers coloured black, dark grey, grey, light grey, and white) are unchanged with changes in overall intensity (i.e., in the level of illumination of the papers). He proposed, in his famous1961 paper entitled "To Honor Fechner and Repeal His Law", that intensity of stimulation is related to perception via a power-law.
Fechner's general formula for getting at the number of units in any sensation isS = c log R, whereS stands for the sensation,R for the stimulus numerically estimated, andc for a constant that must be separately determined by experiment in each particular order of sensibility. Fechner's reasoning has been criticized on the grounds that although stimuli are composite, sensations are not. "Every sensation," saysWilliam James, "presents itself as an indivisible unit; and it is quite impossible to read any clear meaning into the notion that they are masses of units combined."[10]
In 1838, he also studied the still-mysterious perceptual illusion of what is still called theFechner color effect, whereby colors are seen in a moving pattern of black and white. The English journalist and amateur scientistCharles Benham, in 1894, enabled English-speakers to learn of the effect through the invention of the spinning top that bears his name, Benham's top. Whether Fechner and Benham ever actually met face to face is not known.
In hisVorschule der Aesthetik (1876) he used the method of extreme ranks for subjective judgements. Two years later he published a paper which developed the notion of themedian and is generally credited with introducing the median into the formal analysis of data.[12] He later exploredexperimental aesthetics and attempted to determine the shapes and dimensions of aesthetically pleasing objects, using as a database the sizes of paintings.[13]
In 1871, Fechner reported the first empirical survey of coloured letter photisms among 73synesthetes.[14][15] His work was followed in the 1880s by that ofFrancis Galton.[16][17][18]
One of Fechner's speculations about consciousness dealt with brain. During his time, it was known that the brain is bilaterally symmetrical and that there is a deep division between the two halves that are linked by a connecting band of fibers called thecorpus callosum. Fechner speculated that if thecorpus callosum were split, two separate streams of consciousness would result - the mind would become two. Yet, Fechner believed that his theory would never be tested; he was incorrect. During the mid-twentieth century,Roger Sperry andMichael Gazzaniga worked on epileptic patients with sectioned corpus callosum and observed that Fechner's idea was correct.[19]
Fechner constructed ten rectangles with different ratios of width to length and asked numerous observers to choose the "best" and "worst" rectangle shape. He was concerned with the visual appeal of rectangles with different proportions. Participants were explicitly instructed to disregard any associations that they have with the rectangles, e.g. with objects of similar ratios. The rectangles chosen as "best" by the largest number of participants and as "worst" by the fewest participants had a ratio of 0.62 (21:34).[20] This ratio is known as the "golden section" (orgolden ratio) and referred to the ratio of a rectangle's width to length that is most appealing to the eye.Carl Stumpf was a participant in this study.
However, there has been some ongoing dispute on the experiment itself, as the fact that Fechner deliberately discarded results of the study ill-fitting to his needs became known, with many mathematicians, includingMario Livio, refuting the result of the experiment.[21]
In his posthumously publishedKollektivmasslehre (1897), Fechner introduced the Zweiseitige Gauss'sche Gesetz ortwo-piece normal distribution, to accommodate the asymmetries he had observed in empirical frequency distributions in many fields. The distribution has been independently rediscovered by several authors working in different fields.[22]
In 1861, Fechner reported that if he looked at a light with a darkened piece of glass over one eye then closed that eye, the light appeared to become brighter, even though less light was coming into his eyes.[23] This phenomenon has come to be calledFechner's paradox.[24] It has been the subject of numerous research papers, including in the 2000s.[25] It occurs because the perceived brightness of the light with both eyes open is similar to the average brightness of each light viewed with one eye.[23]
Fechner, along withWilhelm Wundt andHermann von Helmholtz, is recognized as one of the founders of modern experimentalpsychology. His clearest contribution was the demonstration that because the mind was susceptible to measurement and mathematical treatment, psychology had the potential to become a quantified science. Theorists such asImmanuel Kant had long stated that this was impossible, and that therefore, a science of psychology was also impossible.
Though he had a vast influence onpsychophysics, the actual disciples of his general philosophy were few.Ernst Mach was inspired by his work on psychophysics.[26]William James also admired his work: in 1904, he wrote an admiring introduction to the English translation of Fechner'sBüchlein vom Leben nach dem Tode (Little Book of Life After Death).
Furthermore, he influencedSigmund Freud, who refers to Fechner when introducing the concept of psychic locality in hisThe Interpretation of Dreams that he illustrates with the microscope-metaphor.[28][29][30]
Fechner's world concept was highlyanimistic. He felt the thrill of life everywhere, in plants, earth, stars, the total universe. Fechner was a panpsychist; he viewed the entire universe as being inwardly alive and consciously animated, instead of being dead “stuff” as accepted by most of his contemporary colleagues, who had become devotees to what was becoming known as material science. Yet he based his panpsychism on a well thought out description of consciousness as waves. He believed that human beings stand midway between the souls of plants and the souls of stars, who are angels.[31] God, the soul of the universe, must be conceived as having an existence analogous to human beings. Natural laws are just the modes of the unfolding of God's perfection. In his last work Fechner, aged but full of hope, contrasts this joyous "daylight view" of the world with the dead, dreary "night view" ofmaterialism. Fechner's work inaesthetics is also important. He conducted experiments to show that certain abstract forms and proportions are naturally pleasing to our senses, and gave some new illustrations of the working of aesthetic association.[10]Charles Hartshorne saw him as a predecessor on his andAlfred North Whitehead's philosophy and regretted that Fechner's philosophical work had been neglected for so long.[32]
Fechner's work continues to have an influence on modern science, inspiring continued exploration of human perceptual abilities by researchers such asJan Koenderink,Farley Norman,David Heeger, and others.
In 1985 the International Society for Psychophysics called its annual conferenceFechner Day. The conference is now scheduled to include 22 October to allow psychophysicists to celebrate the anniversary of Fechner's waking up on that day in 1850 with a new approach into how to study the mind.[34] Fechner Day runs annually with the 2021 Fechner Day being the 37th.[35] It is organized annually, by a different academic host each year.[36][37][38] During the pandemic resulting from COVID-19, Fechner Day was held online in 2020 and 2021.
^abcMichael Heidelberger (2004). "1: Life and Work".Nature from within: Gustav Theodor Fechner and his Psychophysical Worldview. University of Pittsburgh Press. p. 21.ISBN9780822970774.The study of medicine also contributed to a loss of religious faith and to becoming atheist.
^Beiser, Frederick C. (2024),"Gustav Theodor Fechner", in Zalta, Edward N.; Nodelman, Uri (eds.),The Stanford Encyclopedia of Philosophy (Summer 2024 ed.), Metaphysics Research Lab, Stanford University, retrieved2024-09-07
^Beiser, Frederick C."Gustav Theodor Fechner".Stanford Encyclopedia of Philosophy. Retrieved13 July 2022.
^Fechner, G. (1876)Vorschule der Aesthetik. Leipzig: Breitkopf und Hartel. Website:chuoft.pdf
^Campen, Cretien van (1996). De verwarring der zintuigen. Artistieke en psychologische experimenten met synesthesie.Psychologie & Maatschappij, vol. 20, nr. 1, pp. 10–26.
^For Hartshorne's appreciation of Fechner see hisAquinas to Whitehead – Seven Centuries of Metafysics of Religion. Hartshorne also comments that William James failed to do justice to the theological aspects of Fechner's work. Hartshorne saw also resemblances with the work of Fechner's contemporaryJules Lequier. See also: Hartshorne – Reese (ed.)Philosophers speak of God.
^Fechner, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
^Kreuger, L. E. (1993) Personal Communication. ref History of Psychology 4th edition David Hothersal 2004ISBN9780072849653
Heidelberger, M. (2001), "Gustav Theodor Fechner" inStatisticians of the Centuries (ed.C. C. HeydeE. Seneta) pp. 142–147. New York:Springer Verlag, 2001.
Heidelberger, M. (2004),Nature From Within: Gustav Theodor Fechner and his Psychophysical Worldview (trans. Cynthia Klohr), Pittsburgh, PA:University of Pittsburgh Press, 2004.ISBN0-822-9421-00
Robinson, David K. (2010), "Gustav Fechner: 150 years of Elemente der Psychophysik", inHistory of Psychology, Vol 13(4), Nov 2010, pp. 409–410.APA PsycNet
Stigler, Stephen M. (1986),The History of Statistics: The Measurement of Uncertainty before 1900, Cambridge, MA:Harvard University Press, pp. 242–254.
