Gustav Fechner

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The German experimental psychologist Gustav The odor Fechner (1801-1887) founded psychophysics and formulated Fechner's law, a landmark in the emergence of psychology as an experimental science.

Gustav Theodor Fechner was born on April 19, 1801, at Gross-Särchen, Lower Lusatia. He earned his degree in biological science in 1822 at the University of Leipzig and taught there until his death on Nov. 18, 1887. Having developed an interest in mathematics and physics, he was appointed professor of physics in 1834.

About 1839 Fechner had a breakdown, having injured his eyes while experimenting on afterimages by gazing at the sun. His response was to isolate himself from the world for 3 years. During this period there was an increase in his interest in philosophy. Fechner believed that everything is endowed with a soul; nothing is without a material basis; mind and matter are the same essence, but seen from different sides. Moreover, he believed that, by means of psychophysical experiments in psychology, the foregoing assertions were demonstrated and proved. He authored many books and monographs on such diverse subjects as medicine, esthetics, and experimental psychology, affixing the pseudonym Dr. Mises to some of them.

The ultimate philosophic problem which concerned Fechner, and to which his psychophysics was a solution, was the perennial mind-body problem. His solution has been called the identity hypothesis: mind and body are not regarded as a real dualism, but are different sides of one reality. They are separated in the form of sensation and stimulus; that is, what appears from a subjective viewpoint as the mind, appears from an external or objective viewpoint as the body. In the expression of the equation of Fechner's law (sensation intensity = C log stimulus intensity), it becomes evident that the dualism is not real. While this law has been criticized as illogical, and for not having universal applicability, it has been useful in research on hearing and vision.

Fechner's most significant contribution was made in his Elemente der Psychophysik (1860), a text of the "exact science of the functional relations, or relations of dependency, between body and mind," and in his Revision der Hauptpunkte der Psychophysik (1882). Upon these works mainly rests Fechner's fame as a psychologist, for in them he conceived, developed, and established new methods of mental measurement, and hence the beginning of quantitative experimental psychology. The three methods of measurement were the method of just-noticeable differences, the method of constant stimuli, and the method of average error. According to the authorities, the method of constant stimuli, called also the method of right and wrong cases, has become the most important of the three methods. It was further developed by G. E. Müller and F. M. Urban.

William James, who did not care for quantitative analysis or the statistical approach in psychology, dismisses the psychophysic law as an "idol of the den," the psychological outcome of which is nothing. However, the verdict of other appraisers is kinder, for they honor Fechner as the founder of experimental psychology.

Further Reading

The major biographies of Fechner are in German. An account of him in English, with the original German bibliography, is in G. Stanley Hall, Founders of Modern Psychology (1912). For a treatment of Fechner's works and thought see T. Ribot, German Psychology of Today: The Empirical School (trans. 1886). For his philosophy see O. Klemm, History of Psychology (1911; trans. 1914), and George Sidney Brett, History of Psychology, vol. 3 (1921).

Fechner, Gustav Theodor (Groß Särchen, Lausitz, 1801-87, Leipzig), attempted, as a psychologist and philosopher, to adjust idealistic philosophy to 19th-c. science; all branches of science should, according to him, be incorporated in metaphysics. He rejected the notion of an a priori concept of God, and sought to replace it by a pragmatic notion of God as we sense him in the world and within us.

Fechner's special contribution to psychology lay in his renewed investigation into the relationship of body and soul: according to his psychophysics, there is a parallel development in physical substance and the soul, there being no substance (including the planets, the stars, and the earth) without soul. Fechner's views on aesthetics, which he terms in his Vorschule der Ästhetik (2 vols., 1876, 2nd edn. 1898) ‘Ästhetik von unten’, are based on experiments with sensuous reactions. Über das höchste Gut (1848) deals with his views on ethics. Of his numerous publications Elemente der Psychophysik (2 vols., 1860) is the most important.

As a writer of humorous sketches etc. (Stapelia mixta, 1824; Gedichte und Satiren, 1841; Rätselbüchlein, 1850) he used the pseudonym Dr Mises.

Fechner, Gustav Theodor (1801-87) German psychophysicist, and one of the founders of experimental psychology. Fechner studied physiology, but turned to physics which he taught at Leipzig. Philosophically Fechner defended a monism in which the one world can be seen in one way physically and in the other mentally (his analogy was with a line that from one point of view traces a convex curve; from another a concave curve). Experimentally he sought to confirm this insight by discovering close quantitative relationships between conscious experience and physiological stimulus, eventually discovering the law that the intensity of a sensation increases as the log of the stimulus (S = k log R) characterizing psychophysical relations. His Element der psychophysik (1860) is often supposed to mark the beginning of experimental psychology.

1801-1887

Gustav Fechner, German physician, physicist, and philosopher, was born on April 19, 1801, in Gross-Sächen, Prussia, and died in Leipzig on November 18, 1887. Freud admired Fechner as the pioneer of psychophysics and a founder of scientific and experimental psychology. Together with his boyhood friend Eduard Silberstein, Freud attended Fechner's lectures in Leipzig in 1874.

Fechner studied medicine at the University of Leipzig. While still a student, he began writing articles (under the pseudonym Dr. Mises) that satirized contemporary science, and he did not become a practicing physician after receiving his degree. Instead, he turned his interest to physics and mathematics. His research demonstrating the validity of Ohm's laws in relation to a galvanic current led to his appointment as professor of physics in 1834. About 1839 Fechner was forced to leave his academic post due to an eye ailment that he attributed to exhausting research in optics. In his diary, which has been preserved at the University of Leipzig, Fechner described his experiences while ill and the existential crisis and depression that followed.

In the wake of his illness, Fechner developed his interest in sensation, the relation of mind to body, and panpsychism. "The great G. T. Fechner," as Freud called him, was appointed professor of philosophy and anthropology in 1843. In the course of this second creative period, he set out the foundations of psychophysics, such as the Fechner-Weber law, by which he is remembered as a founder of experimental psychology. His two-volume Elemente der Psychophysik was published in 1860.

Fechner's ambitions extended beyond experimental research. He hoped to organize psychophysics and metaphysics in a way that united philosophy and the human sciences. Major works toward fulfilling this aim include his 1848 article on the pleasure principle and Einige Ideen zur Schöpfungsund Entwicklungsgeschichte des Organismen (Certain ideas on the creation and development of organisms; 1873). In this latter work Fechner offers the "principle of constancy" to explain how a progressively ordered and structured system can evolve from a disorganized state, a notion that suggests Freud's famous formula, "Where id was there ego shall be." (In this sense Fechner was also a precursor of the theory of the ego's self-organization [see, for example, Prigogine and Glansdorff].) Although Fechner's works inspired Freud when he conceived his concepts of the pleasure principle and the death instinct (Nitzschke), a systematic study tends to demonstrate that they were separated by fundamental differences in outlook.

Bibliography

Fechner, Gustav Theodor. (1848).Über das lustpinzip des handelns. Zeitschrift für philosophie und philosophische kritik, 19, 1-30; 163-194.

——. (1860). Elemente der psychophysik. Leipzig: Breitkopf und Härtel.

——. (1873). Einige ideen zur schöpfungsund entwicklungsgeschichte der organismen. Leipzig: Bretkopf und Härtel.

Lowrie, Walter (Ed.). (1946). Religion of a scientist: selections from Gustav Theodor Fechner. New York: Pantheon.

Nitzschke, Bernd. (1989). Freud et Herbert Silberer: Hypothèses concernant le destinataire d'une lettre de Freud de 1922. Revue internationale d'histoire de la psychanalyse, 2, 267-277.

Prigogine, Ilya, and Glandsdorf, P. (1973). L'écart à l'équilibre interprété comme une source d'ordre structure dissipatives. Bulletin de la classe des sciences, 59, 672-702.

—BERND NITZSCHKE

(1801–87). German philosopher and physicist, the son of a village pastor. He took his degree in medicine in the University of Leipzig, where he remained for the rest of his life. Fechner's interests soon turned to mathematics and physics, and for a time he earned his living by translating scientific texts from French into German. He also undertook some research on electricity which won him the chair of physics at Leipzig at the early age of 33. Owing to a serious nervous breakdown, he resigned from his chair after a few years and, on recovering, with a deepened religious consciousness, he became a convinced pantheist.

Fechner's fame rests largely on his two-volume work Elemente der Psychophysik (1860). Basing his argument on E. H. Weber's work on differential sensitivity, Fechner argued that, in a series of sensations of increasing magnitude, say brightness or pressure, the intensity of the stimulus must increase in geometrical proportion if a just noticeable difference (j.n.d.) in sensation is to result. Further, if such just noticeable differences could be regarded as units each greater by one than its predecessor, it follows that the intensity of sensation is proportional to the logarithm of the stimulus. This is known as the Weber–Fechner law (also known as Weber's law), which Fechner regarded as basic to our understanding of the relationship between body and mind. It is the first formulation of this relationship in quantitative terms (see psychophysics for further discussion).

Fechner insisted that what he called 'outer psychophysics', i.e. the correlation of sensory magnitude with the intensity of physical stimulation, would eventually be replaced by 'inner psychophysics', i.e. the correlation of subjective magnitude with the intensity of the central excitatory process. He thought that ultimately it would make possible a quantitative treatment not only of sensory magnitude but also of images, feelings, and indeed states of consciousness generally. Unfortunately, techniques were not available in his time to achieve this aim, but developments in contemporary neuropsychology might at least suggest that such an aim is not wholly fanciful.

(Published 1987)

— O. L. Zangwill

Bibliography
• Fechner, G. T. (1860). Elemente der Psychophysik, vols. i and ii (vol. i trans. H. E. Adler, and eds. D. H. Howes and E. G. Boring, 1967).
• Ross, H. E., and Murray, D. J. (trans.) (1978). E. H. Weber: The Sense of Touch. De Tactu and Der Tastinn.

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