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A Review
Henri Louis Bergson's Book
Time and Free Will
Chapter I: The Intensity of Psychic States
Topic 13: Sensation of Light
by Doug Renselle
Doug's Pre-review Commentary
Start of Review






Bibliography Author's
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Conclusion Index

Move to any Topic of Henri Louis Bergson's Time and Free Will,
or to beginning of its review via this set of links
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Topic 13...............Sensation of Light


(Most quotes verbatim Henri Louis Bergson, some paraphrased.)

(Relevant to Pirsig, William James Sidis, and Quantonics Thinking Modes.)


"Shall we call the intensity of light a quantity, or shall we treat it as a quality? It has not perhaps
The sensation of light. Qualitative changes of colour interpreted as quantitative changes in intensity of luminous source. It has not perhaps been sufficiently noticed what a large number of different factors cooperate in daily life in giving us information about the nature of the luminous source. We know from long experience that, when we have a difficulty in distinguishing the outlines and details of objects, the light
is at a distance or on the point of going out. Experience has taught us that the affective sensation or nascent dazzling that we experience in certain cases must be attributed to a higher intensity of the cause. Any increase or diminution in the number of luminous sources alters the way in which the sharp lines of bodies stand out and also the shadows which they project."

(Our bold, color, violet bold italic problematics and violet bold problematics.)

Bergson restarts his footnote counts on each page. So to refer a footnote, one must state page number and footnote number.

Our bold and color highlights follow a code:

  • black-bold - important to read if you are just scanning our review
  • orange-bold - text ref'd by index pages
  • green-bold - we see Bergson suggesting axiomatic memes
  • violet-bold - an apparent classical problematic
  • blue-bold - we disagree with this text segment while disregarding context of Bergson's overall text
  • gray-bold - quotable text
  • red-bold - our direct commentary

We feel obliged to answer Bergson's first sentence question, and just do it outright. Light is qualitative, just as we earlier exclaimed in our page 45 comments that sound is qualitative. Light is a quality! Sound is a quality! All quantum actual manifestations of reality are qualities. Why? How? Reality is quantum flux and quantum fluxings' amplitudes qualitative~characteristics are probabilities (i..e., stochastics; see PPL)! Probabilities (i..e., stochastics; see PPL) are n¤t classically, certainly quantifiable.

We didn't know, when we did this review in early 2001, how to burrow deeply into quantum issues of lightings, and Doug isn't sure how much value it adds here nearly a decade later. Just in case you are interested, see Doug's more recent CeodE 2008-2009 efforts on quantum~scintillation. Doug - 4Jun2009.



"Still more important are the changes of hue which coloured surfaces, and even the pure colours of the spectrum, undergo under the influence of a brighter or dimmer light. As the luminous source is brought nearer, violet takes a bluish tinge, green tends to become a whitish yellow, and red a brilliant yellow. Inversely, when the light is moved away, ultramarine passes into violet and yellow into green; finally, red, green and violet tend to become a whitish yellow. Physicists have remarked these changes of hue for some time; (1) but what is still more remarkable is that the majority of men do not perceive them, unless they pay attention to them or are warned of them. Having made up our mind, [classically] once for all, to interpret changes of quality as changes of quantity, we begin by asserting that every object has its own peculiar colour, definite and invariable. And when the hue of objects tends to become yellow or blue, instead of saying that we see their colour change under the influence of an increase or diminution of light, we assert that the colour remains the same but that our sensation of luminous intensity increases or diminishes. We thus substitute once more, for the qualitative impression received by our consciousness, the quantitative interpretation given by our [SOMwitted CTM] understanding."

Note (1): Rood, Modern Chromatics, (1879), pp. 181-187.

(Our brackets, bold , color, links, and violet bold italic problematics.)








"Helmholtz has described a case of interpretation of the same kind, but still more complicated: "If we form white with two colours of the spectrum, and if we increase or diminish the intensities of the two coloured lights in the same ratio, so that the proportions of the combination remain the same, the resultant colour remains the same although the relative intensity of the sensations undergoes a marked change. . . . This depends on the fact that the light of the sun, which we consider as the normal white light during the day, itself undergoes similar modifications of shade when the luminous intensity varies." (1)

"But yet, if we often judge of variations m the luminous source by the relative changes of hue of
Does experiment prove that we can measure directly our sensations of light? the objects which surround us, this is no longer the case in simple instances where a single object, e.g. a white surface, passes successively through different degrees of luminosity. We are bound to insist particularly on
this last point. For the physicist speaks of degrees of luminous intensity as of real quantities: and, in fact, he measures them by the photometer. The psychophysicist goes still further: he maintains that our eye itself estimates the intensities of light. Experiments have been attempted, at first by Delbœuf, (2) and afterwards by Lehmann and Neiglick, (3) with the view of constructing a psychophysical formula from the direct measurement of our luminous sensations."

Note (1): Handbuch der Physiologischen Optik, 1st ed. (1867), pp. 318-319.

Note (2): Eléments de psychophysique, Paris, 1883.

Note (3): See the account given of these experiments in the Revue philosophique, 1887, Vol. i, p. 71, and Vol. ii, p. 180.

(Our bold , color, and violet bold italic problematics.)









"Of these experiments we shall not dispute the result, nor shall we deny the value of photometric processes; but we must see how we have to interpret them.

"Look closely at a sheet of paper lighted e.g. by four candles, and put out in succession one, two,
Photometric experiments. We perceive different shades and afterwards interpret them as decreasing intensities of white light. three of them. You say that the surface remains white and that its brightness diminishes. But you are aware that one candle has just been put out; or, if you do not know it, you have often observed a similar change in the appearance of a white surface when the illumination was
diminished. Put aside what you remember of your past experiences and what you are accustomed to say of the present ones; you will find that what you really perceive is not a diminished illumination of the white surface, it is a layer of shadow passing over this surface at the moment the candle is extinguished. This shadow is a reality to your consciousness, like the light itself. If you call the first surface in all its brilliancy white, you will have to give another name to what you now see, for it is a different thing: it is, if we may say so, a new shade of white. We have grown accustomed, through the combined influence of our past experience and of physical theories, to regard black as the absence, or at least as the minimum, of luminous sensation, and the successive shades of grey as decreasing intensities of white light."

(Our bold, color, and violet bold italic problematics.)








54 "But, in point of fact, black has just as much reality for our consciousness as white, and the decreasing intensities of white light illuminating a given surface would appear to an unprejudiced consciousness as so many different shades, not unlike the various colours of the spectrum. This is the reason why the change in the sensation is not continuous, as it is in the external cause, and why the light can increase or decrease for a certain period without producing any apparent change in the illumination of our white surface: the illumination will not appear to change until the increase or decrease of the external light is sufficient to produce a new quality. The variations in brightness of a given colour—the affective sensations of which we have spoken above being left aside—would thus be nothing but qualitative changes, were it not our custom to transfer the cause to the effect and to replace our immediate impressions by what we learn from experience and science. The same thing might be said of degrees of saturation. Indeed, if the different intensities of a colour correspond to so many different shades existing between this colour and black, the degrees of saturation are like shades intermediate between this same colour and pure white. Every colour, we might say, can be regarded under two aspects, from the point of view of black and from the point of view of white. And black is then to intensity what white is to saturation."

(Our bold, color, violet bold italic problematics and violet bold problematics.)





In other words, classical science forces its adherents to misinterpret quantum, qualitative reality! Bravo! Bravo Bergson!



"The meaning of the photometric experiments will now be understood. A candle placed at a
photometric experiments
physicist compares,
not sensations but physical effects.
certain distance from a sheet of paper illuminates it in a certain way: you double the distance and find that four candles are required to produce the same sensation. From this you conclude that if you had doubled the distance
without increasing the intensity of the luminous source, the resultant illumination would have been only one-fourth as bright. But it is quite obvious that you are here dealing with the physical and not the psychological effect. For it cannot be said that you have compared two sensations with one another: you have made use of a single sensation in order to compare two different luminous sources with each other, the second four times as strong as the first but twice as far off. In a word, the physicist never brings in sensations which are twice or three times as great as others, but only identical sensations, destined to serve as intermediaries between two physical quantities which can then be equated with one another. The sensation of light here plays the part of the auxiliary unknown quantity which the mathematician introduces into his calculations, and which is not intended to appear in the final result.

"But the object of the psychophysicist is entirely different: it is the sensation of light itself which he studies, and claims to measure."

(Our bold, color, violet bold italic problematics and violet bold problematics.)







This is a crucial observation. This observation rests at physics very heart and soul, and it is physics' own source of its own imminent failure! Quantum reality, due its process' absolute flux, denies any classical idea or concept of identity! Poincaré understood this, too.


56 "Sometimes he will proceed to integrate infinitely small differences, after the method of
The psychophysicist claims to compare and measure sensations. Delbœuf's experiments. Fechner; sometimes he will compare one sensation directly with another. The latter method, due to Plateau and Delbœuf, differs far less than has hitherto been believed from Fechner's: but, as it bears more especially on the luminous sensation we
shall deal with it first. Delbœuf places an observer in front of three concentric rings which vary in brightness. By an ingenious arrangement he can cause each of these rings to pass through all the shades intermediate between white and black. Let us suppose that two hues of grey are simultaneously produced on two of the rings and kept unchanged; let us call them A and B. Delbœuf alters the brightness, C, of the third ring, and asks the observer to tell him whether, at a certain moment, the grey, B, appears to him equally distant from the other two. A moment comes, in fact, when the observer states that the contrast A B is equal to the contrast B C, so that, according to Delbœuf, a scale of luminous intensities could be constructed on which we might pass from each sensation to the following one by equal sensible contrasts: our sensations would thus be measured by one another. I shall not follow Delbœuf into the conclusions which he has drawn from these remarkable experiments the essential question, the only question, as it seems to me, is whether a contrast A B, formed of the elements A and B, is really equal to a contrast B C, which is differently composed."

(Our bold, color, violet bold italic problematics, and violet bold problematics.)







Of course, Bergson is correct, n¤ two macro actualities can ever be classically 'identical' to one another. Indeed, as we show elsewhere in Quantonics, n¤ two Planck quantons are, in general, 'identical.' See our One is the Onliest Number...



"As soon as it is proved that two sensations can be equal without being identical, psychophysics will be established. But it is this equality which seems to me open to question: it is easy to explain, in fact, how a sensation of luminous intensity can be said to be at an equal distance from two others.

"Let us assume for a moment that from our birth onwards the growing intensity of a luminous source
In what case differences of colour might be interpreted as differences magnitude. had always called up in our consciousness, one after the other, the different colours of the spectrum. There is no doubt that these colours would then appear to us as so
many notes of a gamut, as higher or lower degrees in a scale, in a word, as magnitudes. Moreover it would be easy for us to assign each of them its place in the series. For although the extensive cause varies continuously, the changes in the sensation of colour are discontinuous, passing from one shade to another shade. However numerous, then, may be the shades intermediate between the two colours, A and B, it will always be possible to count them in thought, at least roughly, and ascertain whether this number is almost equal to that of the shades which separate B from another colour C. In the latter case it will be said that B is equally distant from A and C, that the contrast is the same on one side as on the other."

(Our bold, color, violet bold italic problematics, and violet bold problematics.)








"But this will always be merely a convenient interpretation: for although the number of intermediate shades may be equal on both sides, although we may pass from one to the other by sudden leaps, we do not know whether these leaps are magnitudes, still less whether they are equal magnitudes: above all it would be necessary to show that the intermediates which have helped us throughout our measurement could be found again inside the object which we have measured. If not, it is only by a metaphor that a sensation can be said to be an equal distance from two others.

"Now, if the views which we have before enumerated with regard to luminous intensities are
This is just the case with differences of intensity in sensations of light. Delbœuf's underlying postulate. accepted, it will be recognized that the different hues of grey which Delbœuf displays to us are strictly analogous, for our consciousness, to colours, and that if we declare that a grey tint is equidistant from two other grey tints, it is in the
same sense in which it might be said that orange, for example, is at an equal distance from green and red. But there is this difference, that in all our past experience the succession of grey tints has been produced in connexion with a progressive increase or decrease m illumination. Hence we do for the differences of brightness what we do not think of doing for the differences of colour: we promote the changes of quality into variations of magnitude. Indeed, there is no difficulty here about the measuring, because the successive shades of grey produced by a continuous decrease of illumination are discontinuous, as being qualities, and because we can count approximately the principal intermediate shades which separate any two kinds of. grey."

(Our bold and color, and violet bold italic problematics.)










"The contrast A B will thus be declared equal to the contrast B C when our imagination, aided by our memory, inserts between A and B the same number of intermediate shades [mean gradations method] as between B and C. It is needless to say that this will necessarily be a very rough estimate. .We may anticipate that it will vary considerably with different persons. Above all it is to be expected that the person will show more hesitation and that the estimates of different persons will differ more widely in proportion as the difference in brightness between the rings A and B is increased, for a more and more laborious effort will be required to estimate the number of intermediate hues. This is exactly what happens, as we shall easily perceive by glancing at the two tables drawn up by Delbœuf. (1) In proportion as he increases the difference in brightness between the exterior ring and the middle ring, the difference between the numbers oil which one and the same observer or different observers successively fix increases almost continuously from 3 degrees to 94, from 5 to 73, from 10 to 25, from 7 to 40. But let us leave these divergences on one side: let us assume that the observers are always consistent and always agree with one another; will it then be established that the contrasts A B and B C are equal?"

Note (1): Eléments de psychophysique, pp. 61, 69.

(Our brackets, bold and color.)







Note, reader, this is 'science's' goal! See Kuhn. Science wants all its practitioners, ideally, to be clones of one another! It is called a "paradigm." Now, consider: Culture... Law... Religion... Sexuality... Truth...


60 "It would first be necessary to prove that two successive elementary contrasts are equal quantities, whilst, in fact, we only know that they are successive. It would then be necessary to prove that inside a given tint of grey we perceive the less intense shades which our imagination has run through in order to estimate the objective intensity of the source of light. In a word, Delbœuf's psychophysics assumes a theoretical postulate of the greatest importance, which is disguised under the cloak of an experimental result, and which we should formulate as follows: "When the objective quantity of light is continuously increased, the differences between the hues of grey successively obtained, each of which represents the smallest perceptible increase of physical stimulation, are quantities equal to one another. And besides, any one of the sensations obtained can be equated with the sum of the differences which separate from one another all previous sensations, going from zero upwards." Now, this is just the postulate of Fechner's psychophysics, which we are going to examine."

(Our bold and color.)

To accomplish this in light/color theory would be analogous mathematics' Peano induction which assumes 1=1.


Quantum science shows us that Planck quanta are probabilistically unequal to one another, in general. I.e., in general, n¤ two Planck quanta ever have identical phases, n¤r loci, n¤r momenta, and so on...

So, we can now show, anticipating Bergson's results, that Fechner flubbed it.


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To contact Quantonics write to or call:

Doug Renselle
Quantonics, Inc.
Suite 18 #368 1950 East Greyhound Pass
Carmel, INdiana 46033-7730

©Quantonics, Inc., 2001-2011 Rev. 4Jun2009  PDR Created: 23Feb2001  PDR
(27Feb2008 rev - Reformat slightly.)
(12Mar2008 rev - Reformat page and index slightly.)
(24Feb2009 rev - Add link to recent QELR of 'aware.' Change wingding font to gif.)
(4Jun2009 rev - Update p. 50 comments.)

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