From the ALWS archives: A selection of papers from the International Wittgenstein Symposia in Kirchberg am Wechsel

1. Outline of the PCS

One well-known objection to Jackson’s knowledge argument is the so-called two-modes-of-presentation-reply famously developed e.g. in Loar’s influential paper “Phenomenal States” (Loar 1990). This reply is based on the Fregean idea that one single, ontological entity can be known under different modes of presentation and aims at saving physicalism by granting just a conceptual gap. Obviously, this idea can be easily formulated on the level of concepts – a move which in this case leads to the notion of phenomenal concepts on the one hand and the notion of physical concepts on the other hand. Once granted these two sorts of concepts defenders of the PCS want to construe the Mary-scenario in analogy to standard cases of co-reference. For the knowledge argument this means that according to the defenders of the PCS the scientist Mary possessed all physical concepts when being confined to her achromatic environment, but acquired new phenomenal ones when seeing for the first time the blue sky. The key-move of the PCS is the claim that these new concepts pick out one single supposed physical referent; e.g. a brain state.

Since the PCS aims at giving an explanation of the Mary-scenario one premise of this strategy is that phenomenal concepts can not be a priori deduced from physical concepts. In other words: The phenomenal concepts Mary gains because of enjoying her first colour-experience are conceptually isolated (Carruthers, Veillet 2007) from all other concepts she had before. Therefore, an explanation why phenomenal concepts are conceptually isolated from physical ones – although both sorts of concepts are taken to pick out one and the same referent – has to be given. Defenders of the PCS hold that such an explanation can be found in important particularities of phenomenal concepts. Hence, according to this account no metaphysical entities such as irreducible Qualia have to be invoked to explain Mary’s new knowledge – it suffices to point out the uniqueness of phenomenal concepts. For this strategy to work in a first step the decisive features of phenomenal concepts have to be elaborated. In a second step it has to be shown that these particularities can explain away the so-called hard problem, viz. the intuition that qualitative experience is not reducible to physical states.

In the following I analyze what happens exactly when Mary gains new knowledge and thereby acquires new concepts. Next, I show that physicalist accounts of phenomenal concepts do not meet the constraint to explain Mary’s epistimic progress and the closely connected dualistic intuitions. Finally, this is compared to my own account of phenomenal concepts labelled theencapsulation account. This account offers an explanation of the brilliant scientist gaining new knowledge but implies decisive features of phenomenal concepts which indicate phenomenal referents. Hence, the PCS fails on both interpretations.

2. The Cognitive Role of Phenomenal Concepts

According to the PCS Mary gains a new concept concerning blue colour-vision when seeing for the first time the blue sky. Since she could not deduce this new phenomenal concept from the other concepts she had before, an explanation for this conceptual isolation has to be given. One explanation is found in the special acquisition-conditions of phenomenal concepts, namely that a person gains a new phenomenal concept iff she undergoes attentively the relevant new experience. This means that phenomenal concepts can not be acquired by description – in fact this is what Jackson’s scenario tells us. All the information about colour vision available to unreleased Mary do not help her in knowing what it is like to see blue and forming the relevant concept.

This way of putting things leads to a second point: When Mary attentively looks at the blue sky and thereby acquires the phenomenal blue-concept she simultaneously makes an epistimic progress, viz. she gains knowledge about the qualitative character of blue-experiences. Therefore, we can conclude that the new phenomenal concept carries information which explains the epistemic development of the scientist. This information has to be about the qualitative character of the blue-experience since this is precisely the information Mary lacked when being confined to her achromatic room and gained when seeing the blue sky. Hence to explain the Mary-scenario, it has to be granted that the new concept carries information about the qualitative character of blue colour-vision and that this information has to be introspectively accessible to Mary.

To sum up the crucial points: The cognitive role of a phenomenal concept is carrying information about qualitative experience and to make this information introspectively available to the person possessing the concept.

Next, let me investigate if physicalist accounts of phenomenal concepts capture this cognitive role. Consider, for example, the demonstrative account of phenomenal concepts, such as the one developed by Levin (2007). The problem of demonstrative accounts is the following: Standard demonstrative concepts typically refer to the item currently demonstrated at and hence their referents differ from one use to another. Therefore, the demonstrative phenomenal concept does not carry itself the relevant information. Furthermore, as Chalmers (2003) pointed out, one can imagine the experience currently demonstrated at as having different character – a thought experiment which can not be performed when employing phenomenal concepts which necessarily carry information about a specific experience.

Next, let me consider the quotational account of the sort invoked by Papineau (2007): On this account phenomenal concepts embed experiences just as quotation marks embed words. How should this analogy be understood? Papineau holds that phenomenal concepts use experiences – hence their particularity can be explained by the special neuronal vehicle in virtue of which the phenomenal concept is realized: “We can helpfully think of perceptual concepts as involving stored sensory templates. These templates will be set up on initial encounters with the relevant referents.” (Papineau 2007, 114)

Here the uniqueness of phenomenal concepts is their involving “stored sensory templates”. This particularity aims at explaining the conceptual isolation and the cognitive role of carrying information about qualitative experiences. But the latter constraint can not be met by a physicalist interpretation of the quotational account. Let me explain why:

On a physicalist interpretation the stored sensory template which is activated in every employing of a phenomenal concept obviously has to be understood as a physical item. Therefore, the pressing question arises: What is meant by “involving” these templates? If this phrase points just at a simultaneous occurrence of concept and neural template, then the phenomenal concept itself does not carry the relevant information. Second, if the neural template should be literally part of the concept then one may wonder a) how a neuronal template can be a constitutive part of a concept and b) how it can carry the information Mary lacked in her achromatic environment. We have to bear in mind that the relevant information is not information about a neural template, but information about a qualitative experience. Obviously, a physical description of a neuronal template leaves the relevant sort of information out. Therefore the physicalist quotational account, which can be interpreted as solely co-occurring with experiences or as involving physical items described in physical terms, fails on both interpretations to explain the cognitive role of phenomenal concepts.

We can conclude that no account of phenomenal concepts which fails to posit an intimate link between these concepts and qualitative experiences can successfully explain the Mary-scenario and our intuitions concerning the hard problem. Therefore, we have to search for an alternative account of phenomenal concepts pointing at specific features which can explain the cognitive role of these concepts and hence also the Mary-scenario.

3. A Proposal

Investigating the Mary-scenario carefully might help working out the crucial particularities of phenomenal concepts. Therefore, let me focus the attention to what Jackson’s knowledge argument teaches us:

In a first step the argument illustrates that a person can gain a new phenomenal concept only under the condition of attentively undergoing the qualitative experience the concept refers to. So concerning the acquisition-conditions of phenomenal concept we can hold that one has to stand in an intimate relationship to the referent. This particularity (which explains also the conceptual isolation) mirrors the fact that no descriptive knowledge suffices to gain a phenomenal concept – it rather requires a sort of acquaintance with the referent itself. Acquaintance is often held as a primitive relation that resists further explanation. But in my opinion some elucidation concerning the process of being acquainted with an item and forming a concept on the basis of this can be given. Let me analyze this process in detail: Mary, who is aware of her very first blue-experience, discriminates this experience from all other current experiences. This act of attentive discrimination immediately yields a concept referring to the particular experience.

The interesting point is what this insight regarding the process of the concept-acquisition tells us about thenature of phenomenal concepts. The situation is the following: Even defenders of the PCS grant that one has to undergo an experience to acquire a phenomenal concept. This condition posits an intimate link between the experience and the phenomenal concept. As we have seen this postulate of an intimate connection between experience and concept is in perfect accordance with the cognitive role of phenomenal concepts. Please remember that phenomenal concepts have to carry information about the qualitative experience to explain Mary’s new knowledge. Hence, the claim of an intimate link between experience and concept is desirable for more than one reason: on the one hand it offers a perfect account of the cognitive role of these concepts and on the other hand it explains their special acquisition-conditions and the closely related feature of conceptual isolation. How can this intimate connection be spelled out in detail?

According to my account only the fact that an experience is self-presenting, i.e. that it serves as its own mode of presentation, enables our awareness of it. As it has been argued this awareness is part of the acquisition-condition of phenomenal concepts – therefore it can be concluded that a person can gain a phenomenal concept only under the condition of being aware of a self-presenting item. The detailed acquisition-process goes the following way: When Mary discriminates a new experience this process of isolation implies giving the experience itself a conceptual structure and hence forming a concept which encapsulates the experience itself. The notion of encapsulation is based on the idea that the experience itself is the core of the phenomenal concept referring to it. Therefore, a careful analysis of the acquisition-process reveals an encapsulation relation between phenomenal concepts and their referents. Obviously, on the proposed account, both concept and referent are mental entities and their relation is constitutive.

Importantly, a concept which encapsulates an item without involving any separate mode of presentation has particular consequences: First, the self-presenting character of the experience guarantees the direct reference of the concept formed on the basis of it. Second, these concepts pick out their referents directly and in all possible worlds – facts which are due to the internal constitution of encapsulation. Decisively, since the reference of phenomenal concepts is fixed by their internal constitution and not by external factors, they carry essential information about the relevant experience. And this is exactly what the knowledge argument tells us about the cognitive role of phenomenal concepts: Mary’s new concepts carry information about the qualitative character of experiences.

The reader might have the impression that the proposed account of phenomenal concepts encapsulating experiences is the same as the above analyzed quotational account. It isn’t. For clarification let me finally work out the decisive differences between these two accounts.

The quotational account which seems to share the herein elaborated interpretation intends to draw a physicalist conclusion. This attempt fails because defending encapsulation implies that phenomenal concepts pick out phenomenal referents. The reasons why are the following: If phenomenal concepts are interpreted as encapsulating their referents, then this unique reference-relation has to be explained. Only an explanation referring to the self-presenting character of experiences can do this explanatory work. If a defender of the quotational accounts grants encapsulation but nevertheless intends to draw a physicalist conclusion from this, she has to give a physicalist account of how a concept can encapsulate a physical item and how this item can carry introspectively accessible information about qualitative experiences. It seems mysterious how this can be done without invoking self-presentation. But self-presentation is a mark of phenomenal entities where there can not be made a distinction between presented and presenting item. Moreover, as we have seen in Papineaus´ work, most defenders of the quotational account abstain to interpret it in analogy to a constitutive encapsulation. They do not refer to an internal constitution of concept and experience but rather to some sort of co-occurrence or unclear notion of the concept “using” the experience.

4. Conclusion

I demonstrated in accordance with the PCS that the new concepts in the Mary-scenario differ in several respects significantly from any other concept-type. Jackson’s knowledge argument teaches us that phenomenal concepts are conceptually isolated and have the cognitive role of carrying introspectively available information about qualitative experiences. I combined this with another outcome of the Mary-scenario; namely that phenomenal concepts have very special acquisition-conditions. Both of these insights are granted by defenders of the PCS and require an explanation. I argued that if defenders of the PCS grant this, they also have to accept that these particularities of phenomenal concepts imply phenomenal referents - since any other physicalist account can not meet the constraint of explaining the decisive particularities of phenomenal concepts; such as their cognitive role. Therefore, if we take the uniqueness of phenomenal concepts seriously, the PCS can not explain away the hard problem – it rather reinforces it.