Theory of Colours


Theory of Colours is a book by Johann Wolfgang von Goethe about the poet's views on the nature of colours and how these are perceived by humans. It was published in German in 1810 and in English in 1840. The book contains detailed descriptions of phenomena such as coloured shadows, refraction, and chromatic aberration.
The work originated in Goethe's occupation with painting and mainly exerted an influence on the arts. The book is a successor to two short essays entitled "Contributions to Optics".
Although Goethe's work was rejected by physicists, a number of philosophers and physicists have concerned themselves with it, including Thomas Johann Seebeck, Arthur Schopenhauer, Hermann von Helmholtz, Rudolf Steiner, Ludwig Wittgenstein, Werner Heisenberg, Kurt Gödel, and Mitchell Feigenbaum.
Goethe's book provides a catalogue of how colour is perceived in a wide variety of circumstances, and considers Isaac Newton's observations to be special cases. Unlike Newton, Goethe's concern was not so much with the analytic treatment of colour, as with the qualities of how phenomena are perceived. Philosophers have come to understand the distinction between the optical spectrum, as observed by Newton, and the phenomenon of human colour perception as presented by Goethe—a subject analyzed at length by Wittgenstein in his comments on Goethe's theory in Remarks on Colour.

Historical background

At Goethe's time, it was generally acknowledged that, as Isaac Newton had shown in his Opticks in 1704, colourless light is split up into its component colours when directed through a prism.
Goethe's starting point was the supposed discovery of how Newton erred in the prismatic experiment, and by 1793 Goethe had formulated his arguments against Newton in the essay "Über Newtons Hypothese der diversen Refrangibilität". Yet, by 1794, Goethe had begun to increasingly note the importance of the physiological aspect of colours.
As Goethe notes in the historical section, Louis Bertrand Castel had already published a criticism of Newton's spectral description of prismatic colour in 1740 in which he observed that the sequence of colours split by a prism depended on the distance from the prism—and that Newton was looking at a special case.
"Whereas Newton observed the colour spectrum cast on a wall at a fixed distance away from the prism, Goethe observed the cast spectrum on a white card which was progressively moved away from the prism... As the card was moved away, the projected image elongated, gradually assuming an elliptical shape, and the coloured images became larger, finally merging at the centre to produce green. Moving the card farther led to the increase in the size of the image, until finally the spectrum described by Newton in the Opticks was produced... The image cast by the refracted beam was not fixed, but rather developed with increasing distance from the prism. Consequently, Goethe saw the particular distance chosen by Newton to prove the second proposition of the Opticks as capriciously imposed."
In the preface to the Theory of Colours, Goethe explained that he tried to apply the principle of polarity, in the work—a proposition that belonged to his earliest convictions and was constitutive of his entire study of nature.

Goethe's theory

It is hard to present Goethe's "theory", since he refrains from setting up any actual theory; he says, "its intention is to portray rather than explain". Instead of setting up models and explanations, Goethe collected specimens—he was responsible for the meteorological collections of Jena University. By the time of his death, he had amassed over 17,800 minerals in his personal collection—the largest in all of Europe. He took the same approach to colour—instead of narrowing and isolating things to a single 'experimentum crucis', he sought to gain as much breadth for his understanding as possible by developing a wide-ranging exposition through which is revealed the essential character of colour—without having to resort to explanations and theories about perceived phenomena such as 'wavelengths' or 'particles'.
"The crux of his color theory is its experiential source: rather than impose theoretical statements, Goethe sought to allow light and color to be displayed in an ordered series of experiments that readers could experience for themselves.". According to Goethe, "Newton's error.. was trusting math over the sensations of his eye.".
To stay true to the perception without resort to explanation was the essence of Goethe's method. What he provided was really not so much a theory, as a rational description of colour. For Goethe, "the highest is to understand that all fact is really theory. The blue of the sky reveals to us the basic law of color. Search nothing beyond the phenomena, they themselves are the theory."
Goethe outlines his method in the essay, The experiment as mediator between subject and object. It underscores his experiential standpoint. "The human being himself, to the extent that he makes sound use of his senses, is the most exact physical apparatus that can exist."

Light and darkness

Unlike his contemporaries, Goethe didn't see darkness as an absence of light, but rather as polar to and interacting with light; colour resulted from this interaction of light and shadow. For Goethe, light is "the simplest most undivided most homogeneous being that we know. Confronting it is the darkness".
Based on his experiments with turbid media, Goethe characterized colour as arising from the dynamic interplay of darkness and light. Rudolf Steiner, the science editor for the Kurschner edition of Goethe's works, gave the following analogy:
Goethe expresses this more succinctly:
In other words: Yellow is a light which has been dampened by darkness; Blue is a darkness weakened by light.

Experiments with turbid media

Goethe's studies of colour began with experiments which examined the effects of turbid media, such as air, dust, and moisture on the perception of light and dark. The poet observed that light seen through a turbid medium appears yellow, and darkness seen through an illuminated medium appears blue.
He then proceeds with numerous experiments, systematically observing the effects of rarefied mediums such as dust, air, and moisture on the perception of colour.

Boundary conditions

When viewed through a prism, the orientation of a light–dark boundary with respect to the prism's axis is significant. With white above a dark boundary, we observe the light extending a blue-violet edge into the dark area; whereas dark above a light boundary results in a red-yellow edge extending into the light area.
Goethe was intrigued by this difference. He felt that this arising of colour at light–dark boundaries was fundamental to the creation of the spectrum.
Varying the experimental conditions by using different shades of grey shows that the intensity of coloured edges increases with boundary contrast.

Light and dark spectra

Since the colour phenomenon relies on the adjacency of light and dark, there are two ways to produce a spectrum: with a light beam in a dark room, and with a dark beam in a light room.
Goethe recorded the sequence of colours projected at various distances from a prism for both cases. In both cases, he found that the yellow and blue edges remain closest to the side which is light, and red and violet edges remain closest to the side which is dark. At a certain distance, these edges overlap—and we obtain Newton's spectrum. When these edges overlap in a light spectrum, green results; when they overlap in a dark spectrum, magenta results.
With a light spectrum, we find yellow-red colours along the top edge, and blue-violet colours along the bottom edge. The spectrum with green in the middle arises only where the blue-violet edges overlap the yellow-red edges. Unfortunately an optical mixture of blue and yellow gives white, not green, and so Goethe's explanation of Newton's spectrum fails.
With a dark spectrum, we find violet-blue along the top edge, and red-yellow along the bottom edge—and where these edges overlap, we find magenta.
Olaf Müller presented the matter in the following way, "According to Newton, all spectral colors are contained in white sunlight, according to Goethe, the opposite can be said — that all colors of the complementary spectrum are contained in the dark."

Goethe's colour wheel

Goethe anticipated Ewald Hering's Opponent process theory by proposing a symmetric colour wheel. He writes, "The chromatic circle... arranged in a general way according to the natural order... for the colours diametrically opposed to each other in this diagram are those which reciprocally evoke each other in the eye. Thus, yellow demands violet; orange blue; purple green; and vice versa: thus... all intermediate gradations reciprocally evoke each other; the simpler colour demanding the compound, and vice versa.
In the same way that light and dark spectra yielded green from the mixture of blue and yellow—Goethe completed his colour wheel by recognising the importance of magenta—"For Newton, only spectral colors could count as fundamental. By contrast, Goethe's more empirical approach led him to recognize the essential role of magenta in a complete color circle, a role that it still has in all modern color systems."

Complementary colours and colours psychology

Goethe also included aesthetic qualities in his colour wheel, under the title of "allegorical, symbolic, mystic use of colour", establishing a kind of color psychology.
He associated red with the "beautiful", orange with the "noble", yellow to the "good", green to the "useful", blue to the "common", and violet to the "unnecessary".
These six qualities were assigned to four categories of human cognition, the rational to the beautiful and the noble, the intellectual to the good and the useful, the sensual to the useful and the common and, closing the circle, imagination to both the unnecessary and the beautiful.

Newton and Goethe

"The essential difference between Goethe’s theory of colour and the theory which has prevailed in science since Newton’s day, lies in this: While the theory of Newton and his successors was based on excluding the colour-seeing faculty of the eye, Goethe founded his theory on the eye’s experience of colour."
"The renouncing of life and immediacy, which was the premise for the progress of natural science since Newton, formed the real basis for the bitter struggle which Goethe waged against the physical optics of Newton. It would be superficial to dismiss this struggle as unimportant: there is much significance in one of the most outstanding men directing all his efforts to fighting against the development of Newtonian optics."
Due to their different approaches to a common subject, many misunderstandings have arisen between Newton's mathematical understanding of optics, and Goethe's experiential approach.
Because Newton understands white light to be composed of individual colours, and Goethe sees colour arising from the interaction of light and dark, they come to different conclusions on the question: is the optical spectrum a primary or a compound phenomenon?
For Newton, the prism is immaterial to the existence of colour, as all the colours already exist in white light, and the prism merely fans them out according to their refrangibility. Goethe sought to show that, as a turbid medium, the prism was an integral factor in the arising of colour.
Whereas Newton narrowed the beam of light in order to isolate the phenomenon, Goethe observed that with a wider aperture, there was no spectrum. He saw only reddish-yellow edges and blue-cyan edges with white between them, and the spectrum arose only where these edges came close enough to overlap. For him, the spectrum could be explained by the simpler phenomena of colour arising from the interaction of light and dark edges.
Newton explains the appearance of white with colored edges by saying that due to the differing overall amount of refraction, the rays mix together to create a full white towards the centre, whereas the edges do not benefit from this full mixture and appear with greater red or blue components. For Newton's account of his experiments, see his Opticks.

Table of differences

Qualities of LightNewton Goethe
HomogeneityWhite light is composed of coloured elements.Light is the simplest most undivided most homogenous thing.
DarknessDarkness is the absence of light.Darkness is polar to, and interacts with light.
SpectrumColours are fanned out of light according to their refrangibility.Coloured edges which arise at light-dark borders overlap to form a spectrum.
PrismThe prism is immaterial to the existence of colour.As a turbid medium, the prism plays a role in the arising of colour.
Role of refractionLight becomes decomposed through refraction, inflection, and reflection.Refraction, inflection, and reflection can exist without the appearance of colour.
AnalysisWhite light decomposes into a spectrum of all colors.There are only two pure colours—blue and yellow; the rest are degrees of these. Citation:
SynthesisJust as white light can be decomposed, it can be put back together.Colours recombine to shades of grey.
Particle or wave?ParticleNeither, since they are inferences and not observed with the senses.
Colour wheelAsymmetric, 7 coloursSymmetric, 6 colours

Goethe's reification of darkness is rejected by modern physics. Both Newton and Huygens defined darkness as an absence of light. Young and Fresnel showed that Huygens’ wave theory could explain that colour is the visible manifestation of light's wavelength. Physicists today attribute both a corpuscular and undulatory character to light—comprising the wave–particle duality.

History and influence

The first edition of the Farbenlehre was printed at the Cotta’schen Verlagsbuchhandlung on May 16, 1810, with 250 copies on grey paper and 500 copies on white paper. It contained three sections: i) a didactic section in which Goethe presents his own observations, ii) a polemic section in which he makes his case against Newton, and iii) a historical section.
From its publication, the book was controversial for its stance against Newton. So much so, that when Charles Eastlake translated the text into English in 1840, he omitted the content of Goethe's polemic against Newton.

Influence on the arts

Goethe was initially induced to occupy himself with the study of colour by the questions of hue in painting. "During his first journey to Italy, he noticed that artists were able to enunciate rules for virtually all the elements of painting and drawing except color and coloring. In the years 1786–88, Goethe began investigating whether one could ascertain rules to govern the artistic use of color."
This aim came to some fulfillment when several pictorial artists, above all Philipp Otto Runge, took an interest in his colour studies. After being translated into English by Charles Eastlake in 1840, the theory became widely adopted by the art world—especially among the Pre-Raphaelites. J. M. W. Turner studied it comprehensively and referenced it in the titles of several paintings. Wassily Kandinsky considered it "one of the most important works."

Influence on Latin American flags

During a party in Weimar in the winter of 1785, Goethe had a late-night conversation with the South American revolutionary Francisco de Miranda. In a letter written to Count Semyon Romanovich Vorontsov, Miranda recounted how Goethe, fascinated with his exploits throughout the Americas and Europe, told him, "Your destiny is to create in your land a place where primary colours are not distorted.” He proceeded to clarify what he meant:

Influence on philosophers

In the nineteenth century Goethe's Theory was taken up by Schopenhauer in On Vision and Colors, who developed it into a kind of arithmetical physiology of the action of the retina, much in keeping with his own representative idealism .
In the twentieth century the theory was transmitted to philosophy via Wittgenstein, who devoted a series of remarks to the subject at the end of his life. These remarks are collected as Remarks on Colour,.
Wittgenstein was interested in the fact that some propositions about colour are apparently neither empirical nor exactly a priori, but something in between: phenomenology, according to Goethe. However, Wittgenstein took the line that 'There is no such thing as phenomenology, though there are phenomenological problems.' He was content to regard Goethe's observations as a kind of logic or geometry. Wittgenstein took his examples from the Runge letter included in the "Farbenlehre", e.g. "White is the lightest colour", "There cannot be a transparent white", "There cannot be a reddish green", and so on. The logical status of these propositions in Wittgenstein's investigation, including their relation to physics, has been discussed in Jonathan Westphal's Colour: a Philosophical Introduction.

Reception by scientists

During Goethe's lifetime countless scientists and mathematicians commented on Goethe's Newton criticism in color theory, namely in reviews, books, book chapters, footnotes, open letters. A large plurality of these votes spoke against Goethe, especially Thomas Young, Louis Malus, Pierre Prévost and Gustav Theodor Fechner. One third of the statements from the natural sciences were in favour of Goethe, in particular Thomas Johann Seebeck, Johann Salomo Christoph Schweigger and Johann Friedrich Christian Werneburg, and one-fifth expressed ambivalence or a draw.
As early as 1853, in Hermann von Helmholtz's lecture on Goethe's scientific works—he says of Goethe's work that he depicts the perceived phenomena—"circumstantially, rigorously true to nature, and vividly puts them in an order that is pleasant to survey, and proves himself here, as everywhere in the realm of the factual, to be the great master of exposition". Helmholtz ultimately rejects Goethe's theory as the work of a poet, but expresses his perplexity at how they can be in such agreement about the facts of the matter, but in violent contradiction about their meaning—'And I for one do not know how anyone, regardless of what his views about colours are, can deny that the theory in itself is fully consequent, that its assumptions, once granted, explain the facts treated completely and indeed simply'.
Although the accuracy of Goethe's observations does not admit a great deal of criticism, his aesthetic approach did not lend itself to the demands of analytic and mathematical analysis used ubiquitously in modern Science.
Much controversy stems from two different ways of investigating light and colour. Goethe was not interested in Newton's analytic treatment of colour—but he presented an excellent rational description of the phenomenon of human colour perception. It is as such a collection of colour observations that we must view this book.
Mitchell Feigenbaum came to believe that "Goethe had been right about colour!"

Current status

"Newton believed that with the help of his prism experiments, he could prove that sunlight was composed of variously coloured rays of light. Goethe showed that this step from observation to theory is more problematic than Newton wanted to admit. By insisting that the step to theory is not forced upon us by the phenomena, Goethe revealed our own free, creative contribution to theory construction. And Goethe's insight is surprisingly significant, because he correctly claimed that all of the results of Newton's prism experiments fit a theoretical alternative equally well.. a century before Duhem and Quine's famous arguments for Underdetermination."
"Goethe’s critique of Newton was not an attack on reason or science, though it has often been portrayed that way.. The critique maintained that Newton had mistaken mathematical imagining as the pure evidence of the senses.. Goethe tried to define the scientific function of imagination: to interrelate phenomena once they have been meticulously produced, described, and organized... Newton had introduced dogma.. into color science by claiming that color could be reduced to a function of rays."
"Although he soon rejected Newton’s differential refrangibility, Goethe always affirmed Newtonian mechanics. It was not an apriori poetic prejudice against mathematical analysis but rather performing the experiments that led him to reject the theory... Goethe soon concluded that in order to explain color one needs to know not just about light but also about eye function and relative differences in light across the visual field."
As a catalogue of observations, Goethe's experiments probe the complexities of human colour perception. Whereas Newton sought to develop a mathematical model for the behaviour of light, Goethe focused on exploring how colour is perceived in a wide array of conditions. Developments in understanding how the brain interprets colours, such as colour constancy and Edwin H. Land's retinex theory bear striking similarities to Goethe's theory.
A modern treatment of the book is given by Dennis L. Sepper in the book, Goethe contra Newton: Polemics and the Project for a New Science of Color.

Quotations

On the catalytic moment