Proper names as identical twins

A while ago I discussed the Bunuel film where different actresses play the same character, and I discussed later how we try to identify people by their faces, or by the sound of their voice. Dogs do the same by their sense of smell, perhaps.

The difference between the film and reality is that Bunuel signifies the identity by convention. The actresses don’t look that alike, certainly not as identical twins look alike. But Bunuel uses cinematic conventions to convey the identity. One actress is seen opening the door, the other is seen walking through the other side. With actual perception the identity is signified naturally.

Before printing, we identified proper names in the same way. Here are two tokens of the word 'Plato' in Worcester 13 9rb and 11vb. With electronic printing, we are used to the same word looking exactly the same, which is guaranteed by the computer representing the five letters in the name 'Plato' by the ASCII characters 80, 108, 97, 116 and 111 respectively. This is what allows us to search an electronic document for the same name, or perform a Google search for ‘Plato’. Even printing on paper guarantees that the letters will look nearly the same.

Before that, we recognised proper names just as we recognised faces.

Face blindness

Hume, Treatise Book I Part iii, section 2 (my emphasis):

We readily suppose an object may continue individually the same, though several times absent from and present to the senses; and ascribe to it an identity, notwithstanding the interruption of the perception, whenever we conclude, that if we had kept our eye or hand constantly upon it, it would have conveyed an invariable and uninterrupted perception. But this conclusion beyond the impressions of our senses can be founded only on the connexion of cause and effect; nor can we otherwise have any security, that the object is not changed upon us, however much the new object may resemble that which was formerly present to the senses.

Back-reference guarantees sameness of subject. Perception doesn’t. Think of the Bunuel film where two actresses (Carole Bouquet and Angela Molina) play the same character (Conchita). I was one of the many people who were fooled into thinking they were the same actress, because of the identity of character. Think also of the meaning of ‘persona’, namely ‘mask’. This idea comes more easily to me I suppose because I suffer from ‘face blindness’. I find it hard to tell when I am meeting the same (relatively unfamiliar) person or not, and rely on tells such as hairstyle, build, age and so on. I am often embarrassed when I meet the same person in the same day but the lighting is different or they have dressed differently and I do not recognise them. I often have to bluff my way out of it. The world of strangers is literally like a world of masks without identity. My wife and daughter guide me through film plots.

Now it might be that perceptual ‘reference’, i.e. reidentification, is some guaranteed and fail safe way of acquiring rapport with the subject, so you always know that the same person is before you. But I think not. I think other people just have better visual processing powers, meaning that a person’s face is a kind of uniquely applying description or ‘look’ that only one person can have. A sort of visual haecceitas, but which is descriptive, for all that. Think of identical twins. Their visual description is the same, so it’s a qualitative identity, not a numerical one.

The Shepard tone

Someone commented (see here and here) about the enigmatic Shepard tone, suggesting it was a case of choosing between the apparently inviolable principle of contradiction, and a phenomenon that apparently contradicted it. I wonder about that.

Look at the Wikipedia definition, which is actually quite good. It says (I paraphrase slightly) it is a tone that continually ascends in pitch, yet which ultimately seems to get no higher. There are two interesting words in that definition, namely 'seems' and 'ultimately', and applying or removing them gives four possible combinations.

(1) The Shepard tone ascends in pitch but does not ascend in pitch

(2) The Shepard tone ascends in pitch but does not seem to ascend in pitch

(3) The Shepard tone ascends in pitch but does not ultimately ascend in pitch

(4) The Shepard tone ascends in pitch but does not ultimately seem to have ascended in pitch

Definition (1) is clearly absurd.  A definition needs to give us a way of distinguishing one thing from another, but this gives us nothing, since it includes pitches which do ascend and those which do not ascend, i.e. includes every kind of pitch whatsoever.  Definition (2) is better, but is it correct?  Surely not. If we take the first two or three tones as they occur in order, they clearly are ascending, and it is not that they just seem to ascend, at least in the initial phases of the sequence.  Both definitions (3) and (4) incorporate the term 'ultimately', and here we are getting somewhere.  What seems paradoxical about the tone is the way that after a full octave has been ascended, we seem to be  back where we were.  It's like one of those Sisyphean nightmares where we seem to be climbing forever, and find ourselves back in the same place.  Or the Blair Witch Project (for those who remember that).  

Yet, in this case at least, is there really any contradiction between appearance and reality?  The whole point of the octave interval is the strong resemblance between the two tones of the interval (say, middle C and top C).  And where there is resemblance or similarity there is (formal) identity.  So it is no paradox to say we are ultimately back in the same place. All the Shepard tone does is to eliminate the respect in which the tones of the interval are different, i.e. eliminates the respect in which C and C' are different, while retaining the similarity.

Why should we find the 'paradox' any more paradoxical than angular movement or modulo change?  If you keep on turning around long enough, you will be facing the same direction again.  It is midnight, then time passes for each successive hour until it is midnight again.  Definition (3) captures the Shepard tone best. It is a tone which ascends in pitch but does not ultimately ascend in pitch, just as an orbit is a movement which changes place but which does not ultimately change in place. What's the problem?
More about the principle of contradiction later.

Sense data according to Hume

Here is a different version of the sense-datum argument from the one you probably learned in the history books.

(1) Although this object looks circular, it is not circular (it's elliptical)
(2) Plates are not elliptical
(3) This object is not a plate
(4) We'll call it a sense-datum
(5) There is nonetheless an actual plate corresponding to the sense-datum.

The argument is valid, unlike the sense-datum arguments parodied and rejected by philosophers like Austin. It starts right away with the premiss that this thing, which you took to be a plate, is not circular at all. It looks circular, but isn't. And if plates are circular, it clearly can't be a plate.

Is the argument sound? Is the first premiss true? Why do we think that the sense-datum is not circular, even though it looks circular? Hume tells us (in connection with a different example, in the Treatise, Book I part iv sec. 2 "Of Scepticism with regard to the Senses") that we come to this 'by reflection' or by 'studied reflection'. Imagination or 'fancy' suggests that the datum is circular, that it is just the way it looks. Reason or reflection tells us that it is not circular. For example, we can look at the datum as an artist sees it and as he represents it in a flat picture, as an ellipse.

The final step of the argument is curious. Why do we suppose there is anything circular there at all? Hume has an interesting theory about this. I paraphrase him as follows. There is naturally an opposition between the two mental forces of imagination and reason, for they are telling us contradictory things. Imagination suggests the datum is circular. Reason and reflection tell us it is not. To set ourselves at ease, we invent a new theory which seems to reconcile both: the philosophical system (i.e. the representative theory of perception) that posits the double existence of the sense-datum and its external object. This satisfies our reason in allowing that the sense-datum is not circular, while agreeing with our imagination in attributing the circularity to something else, which we call an 'object'.

This philosophical system, therefore, is the monstrous offspring of two
principles, which are contrary to each other, which are both at once embrac'd by
the mind, and which are unable mutually to destroy each other.

The imagination tells us, that sense-data have all properties that we commonly suppose them to have (plate sense-data are round, sense-data of straight sticks in the water really are straight). Reflection tells us that they really do not have thise properties. We escape the contradiction between these opinions by a fiction which conforms to both reflection and fancy, by ascribing the contrary features to different things - such as the circularity to the object, the ellipticality to the datum.

Not being able to reconcile these two enemies (reason and fancy), we try "to set ourselves at ease as much as possible, by successively granting to each whatever it demands, and by feigning a double existence, where each may find something, that has all the conditions it desires". Were we fully convinced that the datum was circular we would never run into this idea of a double existence, since we would find satisfaction in the first supposition, without looking any further. Again, if we were fully convinced that the datum was elliptical, we would be as little inclined towards the theory of double existence, since in that case we would clearly perceive the error of the belief that it was circular, and would not bother with it any more.

'Tis therefore from the intermediate situation of the mind, that this opinion
arises, and from such an adherence to these two contrary principles, as makes us
seek some pretext to justify our receiving both; which happily at last is found
in the system of a double existence.

Absolutely my favourite bit of Hume.

A Braille eye (thought experiment)

Imagine the following scenario. Instead of light rays, the page of text before me throws out a film consisting of a braille version of the page, which somehow reaches my eye (Lucretius has a similar idea, though without the Braille). Unlike light, this film is solid and can be felt. Inside my eye is a miniature finger that moves across the film until it finds the word it was looking for (for example ‘dog’).

Two questions: (1) what is the proximate object of my search? Is it the film itself, which the miniature fingertip is feeling its way across? Or is it the original text which emitted the film? (2) How actually is this different from the way that my fovea searches the retinal image? The image stays constant and fixed while my retina moves around it – rather as though the fingertip were attached to the eye, and I had to move the whole eye in order to move the fingertip.

Is Hume an eliminativist about objects?

Hume's philosophy is more radical than we imagine. He did not hold, as Locke held, a representative theory of perception such that our sense impressions are fleeting and perishable, but are representative of objects which are relatively permanent and durable. He held that, when we analyse and examine the world carefully, we find that the things we call tables, chairs and houses really cease to exist when we are not perceiving them. For such things are really identical with our perceptions or sense impressions. He says* "it is impossible for us distinctly to conceive, objects to be in their nature any thing but exactly the same with perceptions". But "it is a gross illusion to suppose, that our resembling perceptions are numerically the same; and it is this illusion, which leads us into the opinion, that these perceptions are uninterrupted, and are still existent, even when they are not present to the senses. " Only philosophical analysis can penetrate and expose this illusion. Even that analysis can fail. The illusion is so strong that as soon as philosophers have discovered it - namely discovered, like Locke and the seventeenth century philosophers of perception, that our sense-impressions are fleeting and impermanent - that they immediately invent a new set of impressions that have the required permanence. Thus the representative theory at once refutes and re-establishes the illusion.

[...] it is liable to the same difficulties; and is over-and-above loaded with this absurdity, that it at once denies and establishes the vulgar supposition. Philosophers deny our resembling perceptions to be identically the same, and uninterrupted; and yet have so great a propensity to believe them such, that they arbitrarily invent a new set of perceptions, to which they attribute these qualities.

Does this make Hume an eliminativist, or a reductionist? I have argued elsewhere that the distinction is arbitrary, and I shall argue that this applies to Hume's position also. If we define 'material object' as something which is mind-independent and permanent, then it is clear Hume is denying the existence of any such things. The only objects we are aware of, he says, are these fleeting and perishable sense-impressions, which have no continued and uninterrupted existence. So he is an eliminativist regarding material objects defined in this way. But as I have argued, we don't have adopt this definition. If we define 'material object' as something identical with our sense-impression, then uninterrupted existence turns into a mere accidental feature of objects. An accidental feature that, as Hume argues, may not apply to any object at all, just as 'carried by the ether' does not apply to light, as people once thought.

In summary: whether Hume is an eliminativist or reductionist about the term 'material object' depends entirely on how you choose to define the term. There are the observable phenomena - the sense impressions - and there is whatever unobservable X explains or underlies these phenomena. And that X can have any features you like. There are no 'essential features' of things that are essentially unobservable.

* A Treatise of Human Nature, Book I. 4. ii - "Of scepticism with regard to the senses". This section is essential reading for any understanding of Hume. People often don't read it because it occurs towards the end of the first book, and because there is a lot of focus on the causation stuff in Part III. Part IV, particularly sections 2-4, are by far the most interesting and enjoyable and indeed strange parts of the work.