Tag Archives: Wolfgang Kohler

Failing to See the Illusion

Every year, there is a competition for who can come up with the best ‘illusion’:


This year’s winner is a dynamic variant of the Ebbinghaus Illusion (by Christopher D. Blair, Gideon P. Caplovitz, and Ryan E.B. Mruczek at University of Nevada Reno):

There are several runners-up including one called ‘A Turn in the Road’ (by Kimberley D. Orsten and James R. Pomerantz, Rice University, Houston):


I can see the dynamic Ebbinghaus effect (although not sure of the difference in seeing it from the side).

However, try as I might I have not been able to see the illusion in the ‘Turn in the Road’.

I don’t see how rearranging the different images alters which one seems to be the odd one out. When the video finishes with an overlap it is unsurprising.

But I think I know what I am supposed to experience. And, perhaps, what is being assumed to be behind this alleged experience.

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Phenomenal Parts

See here for what I mean by ‘obvious’

Note: I define and discuss phenomenal parts in my 2010 Journal of Consciousness Studies paper, Complex Experience, Relativity, and Abandoning Simultaneity. I don’t think my expression of this concept was communicated successfully. I don’t know of anyone who has taken up the idea, however obvious it is to me. I based it on some work around temporal parts and the Brooks/Dainton idea of co-consciousness. Also, I used ‘phenomenal’ in a way not obviously understood by contemporary philosophers use it (as Clare Mac Cumhaill noted to me).

Originally, I wanted to use it in as neutral a way as possible. So, here I’ll develop the idea a little bit.

By ‘phenomenal’, I meant in that previous work (a) what is apparent and (b) what is also acceptable to any theorists in debate around appearances, phenomenology, perception, and so on. So, it doesn’t mean qualia, which certain physicalists dispute. And it doesn’t mean physical events as such, which needn’t be apparent to us.

1. Kohler’s ‘phenomenal objects’

I got this meaning for ‘phenomenal’ from the Gestalt psychologist Wolfgang Kohler’s talk of phenomenal objects (see bibliography for references for the Gestalt archive). In ‘An Old Pseudo-Problem’, Kohler writes ‘Why are the objects of the phenomenal world perceived as before us, outside of ourselves, even though today everybody knows that they depend upon processes inside of us, in the central nervous system?’ Later he argues that physical objects cannot be identified with phenomenal objects, and if any physical objects or processes were to be located at the location of any physical object, it would be the location of the corresponding brain processes:

Under no circumstances has the phenomenal object anything to do with the place in physical space where the “corresponding” physical object is located. If it has to be localized at all at some point in physical space, then obviously it belongs most properly to that place in the brain where the directly corresponding physiological process takes place.

(Koler, ‘An old Pseudo-problem’, Part 1)

What I then take as phenomenal objects in Kohler’s thinking is what is otherwise apparent to us. I take this to be true of Kohler’s view because, otherwise, I think there is none of the tension. There is none of the confusion he claims there to be about what he calls the ‘compulsion to project’  the phenomenal objects into the external world. If by ‘phenomenal object’ he was just talking some non-apparent entities — processes, objects — inside our brains or inside our minds, the only idea we would have about their spatial location is based on quite complex theory, and probably as being inside brains and minds. There would no reason at all to suppose that they are outside in any way. So I take it that for him ‘phenomenal object’ refers to what some other philosophers would call the direct objects of our perception, or what I would also call what we directly perceive.

There might look to be a problem here, I think, in this talk of, on the one hand, the phenomenal objects not being the apparent objects (because the latter appear to be physical objects outside our brains and minds) and, on the other hand, of the phenomenal objects as being in some way apparent to us (as comes from the rest of Kohler’s writing throughout). But I think this tension is resolved if we understand that, for Kohler here, the crucial difference between phenomenal object and physical object is just that particular difference in where each is.

  • The physical object is out there.
  • The phenomenal object is either: (a) in here (by being identified or correlated with brain processes), (b) in some special ‘mind-space’ or (c) not anywhere.

We might say that the phenomenal object lacks externality, meaning the property of being located in the physical world outside our own physical bodies. If we put aside this difference, and any properties that go with it (e.g., as some theorists might think of colour), everything else apparent can belong to the phenomenal object.

2. Parts

Phenomenal parts are like Kohler’s phenomenal objects, but understood in relation to the unity of an experience. They are not just objects but also parts of what we experience.

There is a debate in the philosophy of perception about how experience and what is experienced are related to each other. Some naive and direct realists talk about what we perceive as being components (or parts) of the experience (discussed in Nudds 2009). Other philosophers argue that we do not experience the properties of experience itself, for various reasons; notably, such talk is taken to mean that we experience an experience, which certainly sounds wrong, and for some involves unhelpful ambiguity or regression.

Here, however, I am only concerned with what we experience, rather than other properties that are related to experience otherwise. But it is my view that there is nothing particularly problematic in holding that what we experience is a constituent of the experience itself, conceived as an event (but that is a separate issue).

My talk of ‘parts’ is motivated by what we experience seeming to be a gestalt, as something that is not simple but complex, yet also separate from the rest of the world. Some would take this to mean that what we experience is complex but unified. Being complex, I take it that what we experience has elements or parts. Each of these may be a phenomenal object in Kohler’s sense, or simply the bearer of a phenomenal property (if that is different). What each is not is the entirety of what we experience; that is one reason why I call it a part.

A second reason I do this, I think, is because I am broadly physicalist in my outlook, and work with the assumption that the structural distinctions in perception and experience generally are physical distinctions (or correlated with them). The complexity of what we experience is (or correlated with) a physical complexity. Such physical complexity involves spatially separated parts, and I think, whatever the physicality of phenomenal properties, their bearers are spatially separated from one another.

There is one last reason I use parts, although I think it is better to call this a reason why I don’t avoid talk of parts. The concept of ‘part’ in contemporary metaphysics is not identical to the idea of ‘spatial part’; there is also discussion of ‘temporal parts’, where the existence of something at different times is because it has a different temporal part at each of those times (see Lewis 1998). So, a phenomenal part may not need to mean a spatial part of what we experience. This should make those happy to have the entirety of our immediate and direct experience, including the bearers of the properties that we experience, exist outside of physical space (why-ever they might want that; I don’t myself).

3. ‘Obvious’ instead of ‘phenomenal’

My motivation for introducing the concept of a phenomenal part of what is experienced, and a phenomenal object, is to have something which refers to whatever is both apparent to us and agreed to be how things are. Even if there is nothing different perceptual theorists agree on, at present, about what is apparent and real, or about the constitution of consciousness/perception/experience, etc., it is still the case that, should they eventually do so it would be good to have a term to refer to whatever it is they agree upon. Also, I assumed theorists would agree that what we experience is complex, apparent in some way to us, and separable from the rest of the world, which is why I introduce the ‘part’ talk.[1]

With the Phenomenal Qualities project in the University of Hertfordshire drawing to a close, my use of of ‘phenomenal’ is unfortunately untimely. ‘Phenomenal’, especially ‘phenomenal character’ and ‘phenomenal properties’ seem to be solidifying into meaning ‘qualia’, which are debated in philosophy, and not accepted by everyone. So, my use of ‘phenomenal’ may soon be more trouble than its worth, in that it will probably only generate ambiguities in reading my work with others.

I use ‘obvious’ here instead: What I mean by ‘phenomenal’ in my 2010 and my thesis is what I mean here by ‘obvious’. Thus, phenomenal parts are the obvious parts of an experience, meaning: they are the apparent parts that are also the real parts of an experience.

Last point: Given what it is that one is committed to with ‘obviousness’ (as discussed above), my work presupposes a revelatory theory of experience, as well as for that matter a constitutional theory of experience.  I do not see such commitment to be a bad feature of a theory of experience or perception; but that is a separate issue to what I’m discussing here.


1. My feelings about this now are that such motivations might be not be interpreted as so pure as I think they are, e.g., I imagine some representationalists would resist the general expression of what I offer here.