In his book, Things and Places, Zenon W. Pylyshyn says the following:

What has gone wrong is that we are using the content of phenomenological experience as the explanandum: we are trying to explain the content of the experience by positing certain intrinsic properties of a representation (or, more precisely, of the structure or medium in which the scene is represented). But this makes two untenable assumptions. First, it assumes that the content of experience reflects the content of some mental representation that plays a role in the process of perception and imagination. Secondly, it assumes that the content of thoughts or imaginings reveals the structure and properties of the format or medium in the brain in which the mental representations are expressed. Both these assumptions are victims of the well-known intentional fallacy, the fallacy of attributing properties of what is being represented to the representation itself (as if our representation of a red square were itself red and square).

Two points in particular are difficult to understand:

  • Why would he suggest that anyone would believe that the content of experience is something different from the representation? Unless we posit the idea of the homunculus, it seems we have to consider the experience, phenomenon and representation as different ways of speaking of the same thing.
  • How does he believe that we can access the properties of what is being represented? The optic nerve passes action potentials to the brain, so unless he believes that action potentials can also bear properties from the physical world, he must believe that these properties come by means of ________? Please help me fill in the blank because I don't know what he might be thinking.

I'm not looking for any evidence to support his view. I'm just trying to find a reasonable way of understanding what he could mean.

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Pasnau calls this the "content fallacy", quoting Pylyshyn's alternative description of it as "the seemingly innocent scope slip that lakes image of object X with Property P to mean (image of object X) with property P instead of the correct image of (object X with property P)". He gives some examples of it in Aquinas and the Content Fallacy. It is easy to see the mistake in the blatant example like "Bob is thinking about a red sports car" therefore "Bob's thought is red". But here is a passage from Aquinas's Quaestiones Disputate de Anima:

"An intellective principle of this sort is not something composed of matter and form, because species are received in it entirely immaterially. This is shown by the fact that intellect is concerned with universals, which are considered in abstraction from matter and material conditions."

In other words: intellect receives universals, universals are immaterial, therefore intellect is immaterial. The "syllogism" turns a property of the content into a property of its medium. Aquinas is also doing it in reverse: intellect is immaterial, matter is material, therefore intellect can not "receive" properties of matter directly. As Pasnau points out, "with the one notable exception of Joseph Novak, modern scholars have accepted without qualms the inferences we have been considering", moreover, with the universals replaced by feelings, thoughts or qualia, the "syllogism" is a commonality in the current mind-body dualism debates, see What are the problems with the argument for the mind-body dualism from immateriality of thoughts? Here is Pasnau's explanation:

"But the mistake can be a seductive one. In talking about objects with representational content there is often an ambiguity between the intentional and the intrinsic qualities of the object: that is, our language often fails to distinguish between what an object represents (e.g., a sports car), and what that object is intrinsically like (e.g., organic, plastic, immaterial)."

One is free to have things and their properties built into one's ontology according to whatever scheme, along with their representations and their properties. But whatever the scheme is it has to be consistent (and also plausible): one can not have experience or content bleeding into the format/medium, or vice versa. But the vagueness of language creates pressures for it.

To put it yet another way, functionality is independent of implementation, be it at experience/representation or representation/brain junctures. Brook argues that this functionalist view of the mind was first articulated by Kant, see Why do philosophy of mind courses tend to bypass Kant?

"The basic idea behind functionalism is that the way to model the mind is to model what it does and can do, its functions ('the mind is what the brain does'). The basic idea behind the representational model is that the function of a mind is to shape and transform representations. Kant too had a representational model of the mind (a rather radical one, if my reading of him is right), and his view of the mind as a system for applying concepts to percepts is entirely in line with functionalism... Kant accepted a very strong version of the notion that function does not dictate form. Indeed, his doctrine of the unknowability of the noumenal mind is little more than a strong version of that very idea."

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    I believe saying that a percept is red would be a better choice of words, and I can't imagine why that would be considered a mistake. In fact, it would be entirely consistent with the fact that action potentials do not give us access to the properties of the world. Therefore, I find Pasnau just as much in need of explanation as Pylyshyn. Do they believe that we have some extrasensory means of perceiving of the world?
    – user3017
    Nov 18, 2016 at 23:27
  • @PédeLeão Based on our experience we create models with theoretical entities (such as "action potentials" or "the world"), and then separate them into "reality" and "perception", "object" and "image". The connection between the two is hypothetical, not extrasensory, but to have it the point of the models. If you wish to reduce everything to image and perception that is your prerogative, and it may save you from the content fallacy. But few adopt such view, and for the rest consistency of distinction remains an issue, they would't want any red thoughts or percepts in their models.
    – Conifold
    Nov 19, 2016 at 1:05
  • @PédeLeão Let me put it another way. When we refer to "red" we often mean the public sharable property that can be tracked with say a spectrometer, not the private phenomenal experience, a.k.a quale of red. The content fallacy then roughly corresponds to conflating the two, "red thought" would be a category error, but this example already shows how language invites it. "Roughly", because further distinctions are made in models between "objective" properties of "reality" itself, and those common only in view of our common senses, anatomy, etc.
    – Conifold
    Nov 21, 2016 at 0:36
  • A spectrometer merely quantifies an amount of energy in a way that can be considered analogous to the way that an action potential may represent a particular range of wavelengths. Therefore, what is publicly accessible can be reduced to nothing more than a quantification. Such quantifications have no phenomenal characteristics, so they are hardly suited for being the constituents of an image, and it was images that Pylyshyn was talking about. Therefore, to put it another way, how could we have public access to qualities that could serve as constituents of imagery?
    – user3017
    Nov 21, 2016 at 1:13
  • @PédeLeão The difference between "(image of object X) with property P" and "image of (object X with property P)" is exactly that in the latter property P need not be a phenomenal constituent of an image. At most, it has to correlate with something phenomenal (and I use "correlate" loosely), and not even for everybody, as cases of color blindness show, Is it possible that I see color differently?
    – Conifold
    Nov 21, 2016 at 23:49

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