Monday, 22 April 2013

Tilting at Appearances (Part 3 of 4)


A challenge to Alva Noë’s account of perception, and Sean D. Kelly’s missed opportunities.


Two weeks ago I nearly brought about the tragic deaths of 9 people. We were caught on the ground floor of an unfamiliar building the upper floors of which were filled with what we were told by a fire safety officer was a raging fire belching thick black smoke. It was imperative to get out of the building as quickly and safely as possible and it was my responsibility to lead everyone out of the pitch darkness. Sidling along the walls feeling for doorways and constantly describing my movements whilst asking for a roll call from everyone behind me was stressful to say the least. Eventually in the distance I could make out the tell-tale crack of a doorway and carefully, though perhaps a little overcautiously, I led everyone towards it. 

As we emerged into the light we were met by a fireman from Strathclyde Fire Brigade who informed me that I'd made a fundamental error. Despite my methodical manoeuvres and despite the fact that I'd registered and recovered a straggler from the group, I had missed a doorway that might have led us to safety much earlier in our proceedings. In any other situation I'd have been hailed as a hero for saving everyone but this wasn't any ordinary situation, this was a fire safety simulation at Strathclyde Fire Brigade's newly constructed fire safety training centre. In my determination to overcome the obstacles confronting us I'd made an elementary mistake: I'd failed to take sufficient notice of the contours of the walls and in the process I'd missed a door. No doubt the simulation had been arranged in such a way that the doorway would be difficult to distinguish in the darkness and as such it was obviously intended to point out the importance of swift but comprehensive checks of all tactile clues. In my defence I knew - or thought I knew - that there couldn’t be a genuinely useful doorway so early in the simulation and this presumption had led to my ultimate failure in the task. The moral? In situations that call for vigilance to subtle clues, leave no stone unturned.

At the beginning of a paper from 2006 entitled “Real Presence” (available here) UC Berkeley Philosopher of perception Alva Noë writes:
“A satisfying account of perception must explain how a silver dollar can look both circular and elliptical… The content of perceptual experience is two dimensional, and this needs explaining.”
For Noë, perception (though he only really mentions vision) is a “two step” phenomenon in which we see a silver dollar say, as both circular and elliptical at the same time. Noë cites several theorists who adopt differing opinions on this issue and in the process he makes very little real progress due to his inability or unwillingness to tease out the underlying reasons for his conflicting tendencies to say on the one hand that a tilted coin is elliptical and on the other that it is circular. The vital question that Noë fails to address is how the perception of ellipses (where there are in fact circular objects) might be of use to us as evolved organisms. For him the duality of appearances – the co-existence of what we know and what ‘appears’ – is simply a matter of viewpoint, a visual fact in which two perceptions happily – or at least “commensurably” - coexist:

“Experience contains within it precisely two aspects, or dimensions, to which we can turn our attention.” – Alva Noë

Noë concludes by stating that perception is an encounter with how things “present themselves to a vantage point”. For him perceptions are “ways of coming into contact with the world.” Well, we might not wish to quarrel over these modest claims but then again they are far from the “satisfying account of perception” - let alone a satisfactory one - that we were led to expect from the introductory paragraph. A satisfactory account of perception must explain everything we would subsume under the title of “appearances”, not only the ‘look’ of tilted silver dollars, and by doing so it will, as a consequence, explain a great deal more than how things present themselves to a vantage point or our coming into contact with the world.

To put it bluntly, as admirably clear and diligent as Noë’s method is, he has made exactly the same error as I did in my fire safety training: he has missed a possible route out of the difficulties that he, and thereby we, have found ourselves in, and in the process he leaves us pretty much where we started: in the dark with no real clue of how to make our way out into the light of understanding.

In the same article, Noë cites a 2004 paper by Sean Dorrance Kelly of Harvard University (formerly of Princeton) in which Kelly claims that we are only able to see the similarities between a tilted disk and an elliptical representation if we shift our attention to an “unnatural” attitude; what Kelly calls a “detached attitude”, as opposed to the “natural attitude” of ordinary perception. Kelly argues that this is an especially difficult shift to bring about:
“But we humans have somehow learned to adopt this attitude. I’m not sure how this happened or whether there are animals who can do it. I wouldn’t be surprised though, if our own capacity to adopt this attitude is as little as 600 or so years old, dating back to the discovery of the laws of perspective. Learning to paint realistically, after all, requires learning to adopt the detached perceptual attitude.”
Noë dismisses these speculations by stating that he finds it “impossible to believe” that they are true and in so doing he passes straight by what are admittedly the barely discernable signs of a way out.

And what of Kelly – does he fair any better in navigating the obstacle-ridden shadow-world of appearances? Kelly catches the barest glimpse of the solution but he is already transfixed by a glimmering that he senses in the darkness. After a cursory pause, Kelly’s attention is drawn towards what he believes is a more revealing illumination emanating from the work of French Phenomenologist philosopher, Maurice Merleau-Ponty and as such he is committed to an account of perception  that leads him and us, if we choose to accompany him, headlong into the most stifling and disorientating phenomenological smog.

In a more recent paper Kelly (2009) returns to these issues, once again with Merleau-Ponty in tow, quoting him thus: “To say that a circle seen obliquely is seen as an ellipse is to substitute for our actual perception the schema of what we would have to see if we were cameras.” Of all of the sentences comprising Merleau-Ponty’s oeuvre it is unlikely that Kelly could have selected a more pertinent one and it is no wonder then, that he omits its companion sentence: “In fact, we see a form which oscillates around the ellipse without being an ellipse.” These latter words can only be described as those of someone who barely knows what he is talking about. However, the preceding sentence shows that even Merleau-Ponty has occasional moments of murky inspiration.

So what do the schema of camera vision and the laws of perspective have in common? They are both ways and means of producing a very particular and immensely powerful form of representation, a form of representation that, with the help of technical reproduction, has come to pervade our world. When we find ourselves inclined to say that something ‘looks like’ something else, that it ‘appears’ in such and such a way, what we are in fact demonstrating is that we are aware of how one thing might be substituted by another thing; of how it might be represented to others of our species. The content of perceptual experience is by no means two-dimensional, as Alva Noë seems to think. Only the content of two-dimensional things (principally pictorial representations) is two-dimensional and it is a profound error to fail to notice this fact, especially if you’re seeking to explain appearances.

I never did find out what was on the other side of that door at Strathclyde Fire Safety Training Centre. It might have been firmly locked for all I know. One thing is certain though, if I’d noticed it, I’d have been duty bound to try to open it and if it yielded to my attempt to open it then I would have been duty bound to make a swift but comprehensive evaluation of its potential to lead us to safety.

Tuesday, 9 April 2013

More on Appearances (Part 2 of 4)




"If we attempted to paint an "impressionistic" rendering of your experience, the jangling riot of colour blobs would not capture the content; you do not have the experience of a jangling riot of colour blobs, any more than you have the experience of an ellipse when you look at a penny obliquely." -Daniel Dennett

In a much loved episode of the Irish comedy series “Father Ted” there is a fabulous sketch where the infinitely hapless two main characters (Father Ted and Father Dougal) are holidaying in a caravan attempting to amuse themselves in the middle of a field of cattle. At one point Father Ted decides to explain the theory perspective to Father Dougal with the help of some plastic toy cows.


Father Ted: “Now one last time. These…” [he lifts two plastic cows from the table] “…are small; but the ones out there…” [looking out to some cows beyond the window] “…are far away.”

[Father Dougal shakes his head in bewilderment]

Father Ted: [motioning again with the model cows] “Small.”

Father Ted: [Frowning intently out of the window] “Far away.”
The humour derives from our recognition that given a very warped perception it might just be conceivable that someone of Dougal’s naïve outlook could possibly think that things actually shrink as they recede into the distance. Not even children make this elementary perceptual mistake and why should they, what possible evolutionary advantage could it confer upon them or us, or any other species for that matter?

Notice though that Father Ted makes no reference at any time to the distant cows “appearing” to be small. He gets it exactly right: distant cows are not small and the only reason we would think of them as small would be if we were considering them in the terms of two dimensional representations. The problem is exactly the same as the one that raised such copious commentary in my previous post about tilted disks having the ‘appearance’ of ellipses.

If philosophers and cognitive scientists such as Alva Noë and Daniel Dennett are to be believed, this issue bedevils the form of philosophy known as phenomenology (from Greek: phainómenon, literally the “study” of “that which appears”):

“It’s hard to see how phenomenology could be anything more than earnest pleading as to the supposed revelations of one’s own inner searchings. One phenomenologist says: ‘when I look at a circular coin tilted away I see something elliptical.’ Another phenomenologist demures: ‘circular coins seen tilted don’t look elliptical; rather, they look like circular coins.’ Such a dispute, if it even rises to the level of genuine dispute, does not – indeed, cannot – engage with matters beyond its basic terms; it floats free of questions about the natural world. Phenomenology, conceived this way, makes no meaningful epistemic commitments.” –Alva Noë, “A Critique of Pure Phenomenology” 

Alva Noë fairs a little better in his examination of these kinds of perceptual issues, but what he fails to grasp is the purposefulness of perception: seeing ellipses where there are tilted disks has only one known exploitable function or purpose; to enable the production and consumption of what Donald Brook calls "simulating representations" of tilted circular objects (ie: representations that we, as a species, have characteristic difficulty discriminating from the things they represent under certain circumstances and in certain respects). In Noë's understandable eagerness to distance himself from previous assertions that we perceive the world as a multitude of representations, he makes the mistake of paying insufficient attention to the role of representation in perception.

Like Noë, Walter Hopp of Boston University has some thoughts and observations to add to the debate. Hopp suggests that Noë would be better off jettisoning his claim that we simultaneously perceive tilted disks as both round and elliptical. Hopp may well be correct to make this suggestion but, if he is, we are once again left with an incomplete explanation of why people can be so adamant (artists and representation makers in particular) that they see ellipses where there are clearly tilted circular objects or why a toy cow might ‘appear’ the same size as a real cow situated at a distance.

Perhaps a couple of examples might help to clarify where Noë and Hopp have missed an important point (and where Brook's work sheds some important light). In the following animation the size of a representation of a balloon is enlarged. I’m sure you will predict the outcome, but have a look anyway just to confirm what you already know.

video

Everybody I have shown this to says the same thing: “It looks like the balloon is inflating.” Now have a look at the next animation of a car.

video

What did you perceive? Was it the same as the balloon? Did it appear to inflate or did something else happen? Everyone I have shown this to tells me that they have the impression of an oncoming car. What might seem a little strange though is that exactly the same thing happens in both animations: the image has simply been enlarged over time. But whilst the balloon appears to get bigger, the car appears to move forwards. What we know of the objects depicted is clearly influencing our perception at a fundamental level.

If we didn’t instinctively recognise the characteristic signs of looming vehicles, oncoming fists, or approaching projectiles our chances of survival would be severely limited. Perspectival distortions, as Father Ted knew all to well, provide us with crucially important information about our environment that no other perceptual abilities can achieve so effortlessly.

To speak of appearances – to think of them - is to think of how we could simulate the things seen via the sophisticated strategies of representation. Avoiding oncoming cars and other large or fast moving bodies is often a far more pressing issue.