notes on Diderot’s Letter on the blind   :      for the use of those who can see

 

 

 

Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas; how comes it to be furnished? Whence comes it by that vast store which the busy and boundless fancy of man has painted on it with an almost endless variety? Whence has it all the materials of reason and knowledge? To this I answer in one word, from experience. [1]

 

 

Diderot was fascinated by Locke's dogma that there were no "innate" ideas and that all knowledge was derived from experience. "if a thing has not been perceptible [sensible], one has no representative idea of it". This theory went contrary to Descartes, who argued that there were some ideas, such as God, Mind, Body, or, say a triangle, whose truth could be recognised by reason alone, and therefore could be called "innate". According to Locke, the term "experience" could mean not only sensations (sight, touch, smell etc.) but also reflection [mirror] (i.e. the operation of the mind upon ideas provided by the senses).

 

In his "Traite des Sensations" (1754) Condillac depicts the building up of a human consciousness from sense impressions alone. Possibly influenced by Diderot, he imagined a statue successively endowed with sight ,sense, touch etc., the sense of desire, a sense of its own existence and that of the exterior world.

 

Diderot asked 'what would it be like to be deprived of one of our senses?' The thought that this may change our life in a radical way led him to write his essay 'Letter on the Blind : for the Use of those who can see'  (1749) and 'Letter on the Deaf and Dumb : for the Use those who hear and speak. (1751). He is implying that the "problems" of people lacking a sense are not problems for them alone.

 

 

The letter begins as if in the middle of a conversation, there is no dictat\orial [Upon reaching the end of the pre- (which represents and precedes, or rather forestalls, the presentative production, and, in order to put before the reader's eyes what is not yet visible, is obliged to speak, predict and predicate), the route that has been covered must cancel itself out. But this subtraction leaves a mark of erasure {sous rature} a remainder which is added to the subsequent text and which cannot be completely summed up without it. such an operation thus appears contradictory, and at the same time it is true of the interest one takes in it.

But does a preface exist?]^[2]

Many of Diderot's works begin or exist in the form of supplements, contributions ,or commentaries, to a real or imaginary text. The French verb  'suppléer' means not only to supplement but also to 'continue' or to 'supply what is lacking', or even 'to provide a substitute for'. The letter can be seen as a succession of supplements and digressions. He frequently remarks on this, asking the readers pardon, although this is really a very conscious structural device to punctuate the flow of the narrative and to bring attention to particular points.

 

 

the letter is in four sections

 

 

1          Observations of the 'Blind Man of puiseaux', examining the different metaphysical and ethical values.   

 

Diderot felt that if the blind could be seen to have a different moral code from the sighted, this shows some triumph of relativism. The world is not simply 'there', is has to be constructed by each of us. How will people blind from birth recognise beauty?

 

The subject. "what precise results can one expect from someone who is not used to thinking [réflechir] and reflecting upon himself  [revenir sur lui-même]. absolute blindness - absence of light and absence of awareness simultaneously. A self-conscious and self-reflecting patient would be able to "revenir sur lui-même - to go out of himself and to come back from another place. Sight or blindness are not problematic - the difference between the two states is. For Diderot the metaphor for that difference is the veil. 

 

 

 

 Will they have to have it described to them? They will be immune to physical shame, to vanity? The "blind man of Puiseaux" talks about mirrors. "A machine which puts things in relief far from themselves provided that they are appropriately positioned relative to it. It's like my hand that I do not have to place beside an object to feel it. Diderot explains to him the concept of a mirror, but since it allows sighted people to perceive their own faces, which could otherwise only be perceived through touch, it would seen entirely logical to the blind man that it reproduces the same tactile experience but at a greater distance.

 

Our blind man keeps talking about mirrors you may be sure that he does not know what the word "mirror" means; nevertheless he will never set a looking glass facing the wrong way he speaks as sensibly as we do about the qualities and defects of the organ which he lacks.  If he attaches no idea to the terms which he uses, he at least has this advantage over most other people, that he never misuses terms he speaks so well and so judiciously about things which are absolutely outside his experience that converse with him should do much to weaken the inference we all make - without good reason - from what goes on inside ourselves to what is going on inside others.

 

 

The blind man cannot understand how 'other self' of the mirror can only be seen, not touched.

 

Even if the animal mechanism were as perfect as you claim, and as I would wish to believe, for you are an honourable man and would not wish to deceive me, what has got to do with a supremely intelligent Being? If this perfection in design astonishes you, it is because perhaps you are in the habit of regarding anything you cannot understand as a miracle. I have so often been an object of wonder to you myself that I am not much impressed by your notion of a miracle. I have been an object of awe to people from all over England, who could not conceive how I could do geometry; you must agree that they had a poor conception of general possibilities. does some phenomena strike you as beyond our understanding? Then immediately we say "this is the work of God": our vanity is satisfied with nothing less. Could we put a little less pride into our discourse, and a little more Philosophy?

 

 

 

"your little  machine seems to be putting two senses into contradiction" A more perfect machine would make them agree, though without having to make the objects real. "A third machine might would make them disappear and allow us to realise our error".  The blind man, an intelligent man, can talk about things of which he has no empirical knowledge. He may not know as much as he thinks he does. Unaware of his blindness we accept his findings. Aware of his limitations we take his findings with some scepticism .

 

2          Notes on the problems of imagining for people blind from birth.

 

Diderot asks "how does a person, blind from birth, form an idea of geometrical shapes?" He sees the problem in more general terms as "how does s\he imagine?". Imagination does suppose some ability to separate out objects into some pictorial space, an illusionistic space based on perspective. Diderot's writings assume inevitable differences between representation and object. He describes vision as a mimetic representation and goes on to call a retina "the canvas of this painting". He envisaged a system based on touch. If systems could be memorised by touch some sort of structure could be built up on which would allow a mental system equivalent to "imagination". by repetition a language of relationships could be built up which could equate to "space". Diderot introduces the work of the blind English mathematician Nicholas Saunderson. Diderot's discussion of the blind not only addresses the experience of the blind from birth person  from the viewpoint of the seeing, but also speculates as to the experiences of  the blind speculating on the experiences of the sighted. He also points out their brilliant use of metaphor (expressions heureux)  when discussing things they have no experience of.

 

I have noticed that the paucity [disette] of words also produced the same effect on foreigners to whom the language is not yet familiar: they are forced to say everything with a very small quantity of terms, which constrains them to place some of them very felicitously (again, as with Saunderson, the term is "heureusement" ).  But all language in general being poor in literal words (mot  propres) for writers who have a lively imagination, they are in the same situation as foreigners who have a lot of wit; the situations they invent, the delicate nuances they perceive in characters the naivete of the depictions (peinture) they must execute, separate them at every moment from the ordinary way of speaking and makes them adopt turns of phrase that are admirable when they are not precious or obscure..

 

The Dictionaries etymologize de la gangue française, 5thedition.(Paris P.U.F.,1968), says the word "disette", in part: "perhaps derived from the verb dire in the sense it has in expressions such as trouver  à dire, 'to regret the absence of something. . .' "

 

.

 

Even if the animal mechanism were as perfect as you claim, and as I would wish to believe, for you are an honourable man and would not wish to deceive me, what has got to do with a supremely intelligent Being? If this perfection in design astonishes you, it is because perhaps you are in the habit of regarding anything you cannot understand as a miracle. I have so often been an object of wonder to you myself that I am not much impressed by your notion of a miracle. I have been an object of awe to people from all over England, who could not conceive how I could do geometry; you must agree that they had a poor conception of general possibilities. does some phenomena strike you as beyond our understanding? Then immediately we say "this is the work of God": our vanity is satisfied with nothing less. Could we put a little less pride into our discourse, and a little more Philosophy?

 

 

 

 

"The problem of philosophy's relation to metaphor is that philosophy both makes metaphors that are essential to it and pretends to exclude metaphoricity from what is specific to philosophical discourse. Philosophy closes its eyes in a kind of sleep in which it can continue to act as if  "the meaning aimed at through these figures is an essence rigorously independent of that which carries it over.[ i.e. metaphor].

 

The separation of  independent meaning from the vehicle that meaning is transported is basic to the philosophic definition of metaphor. Derrida points out that that version of metaphor "is already a philosophical thesis, one might even say the sole thesis of philosophy, the thesis which constitutes the concept of metaphor, the opposition between what is proper and what is not, between essence and accident, between intuition and discourse, between thought and language, between intelligible and sensible, and so forth". Representing and Represented.^[3]

 

 

3          Responses to some of these problems by the blind English mathematician and lecturer in optics Nicholas Saunderson, and his imaginary deathbed conversation.

 

Diderot then goes on to invent a 'supplement' in the form of an imaginary deathbed conversation between Saunderson and a priest called Holmes. This puts Diderot in the dual roles of the observer and the observed. Diderot's writings assume inevitable differences between representation and object. He describes vision as a mimetic representation and goes on to call a retina "the canvas of this painting". Diderot suggests that he is more interested in a philosophical than a physiological vision. "I would have less confidence in the response of a blind person who sees for the first time than a philosopher who has meditated in the [dark]". Blindness is an absence that enables one to know what sight is. Blindness is an instance of a truchement^[4]. An interpreter, a spokesman, a representative that causes understanding between differing or opposing parties. Having no language of its own, the "truchement" causes meaning in one idiom to be comprehended in another medium - what in Greek was called metaphorein, to carry over from one to the other. Blindness is this metaphoricy itself and can only be signaled through other metaphors of light and dark. De Man talks of a reader who " has to undergo the explicit results of a vision that is able to move towards the light only because, being already blind, it does not have to fear the power of this light. But the vision is unable to report correctly what it has perceived in the course of its journey"^[5]

 

 

Holmes opens with the argument that the marvels of nature prove the existence of a Creator. Saunderson replies that these were not created for his benefit, that those beauties could only be proof to those who could see them. To have proof of a God he must touch him. He says that Holmes is using language as a metaphor - "seeing the truth", one becomes "enlightened", problems grow "clear" or are "illuminated". This idea of "Nature" and "Beauty" are very much linked to the visual [the eighteenth century's interest in sense experience shows the same interest in the visual as did Plato . . . . the division  between the falseness that we can see and the truth to which we are blinded, or as in Plato,^[6] between the shadows of the cave and the reality of the sun - a blinding reality - ]and it is unlikely that the argument of a blind person would have proceeded in this way. Saunderson makes the point that a person born blind would not see "order" as a primal force in the world.

 

In Saunderson's work Diderot saw a relationship between sensory deprivation and linguistic metaphor. Saunderson's speech was full of "expressions heureuses".[ expressions proper to one sense, touch for example, but metaphoric to another, such as sight , resulting in a double image - the true image and the reflection (metaphor)]

 

For Saunderson there was a surplus of words over 'ideas' because he uses visual words without being able to perceive their referents. For the foreigner or the writer there is a surplus of ideas over words [as in peintures and nuances [nuages]]. It is this breach between idea and language, this truchement that produces metaphors. this metaphor.

      

 

4          The 'Molyneux' problem'

 

First raised by William Molyneux, a doctor friend of Locke's

 

If a person blind from birth were suddenly to see again, were shown a cube and a cylinder, would s/he, just by looking at them, be able to tell the difference?

 

Diderot asked to be present at the operation, but this was refused. Diderot decided that more would be gained by questioning another blind person who had not had their sight restored, but had a philosophical and /or scientific training. Diderot's implication is that one should try inwardness and introspection as much as outward observation and , in a word, do without eyes. Diderot's letter is in the form of an allegory, the paradox of blinding oneself in order to see better as in Democritus blinding himself in order to think better. There is an emphasis on substitution run parallel to a work preoccupied with how a blind person finds substitutes for sight.

 

"it is easy to conceive that the use of one of these senses can be perfected and accelerated by the observations of another; but it is not at all easy to conceive hat between their functions here is an essential dependence

Each sense is self-sufficient, yet at the same time each sense is undermined by the différence [différance] between the object and its representation.

 

 

Vision produces the possibility of seeing perfectly and yet seeing "nothing". Between objects and the retina there is a "nothing", a "truchement" a "difference", that enforces accuracy, but because we see only representations that are different than what created them, "sensations have nothing that resembles objects essentially", we must patrol this space, backwards and forwards, in the act of continual comparison [simile], of the precise conformity between an object and its representation. We see accurately but "seeing" = representing. Diderot saw blindness as a metaphor for this space between object and image and with the language of veils, blindness and ignorance. The lowering of the literal veil (blindness/cataracts) had no effect on the figurative one (blindness/ignorance).

Diderot's interest in blindness [reflects] his belief that vision represents perfectly. His other conviction, that Language can represent anything and everything manifests itself in the Encyclopaedia - a work intended to represent and explain all knowledge - structured as a dictionary of the French language. "A nation's language is a picture of the nation's knowledge".

 

                       

 

David kirshner  www.davidkirshner.org.uk