Stop That Crow!

In last weeks post, Physicalism and its Malcontents, I argued that Frank Jackson’s Knowledge Argument against any kind of physicalist account of the mind depended upon an equivocation on the word “knowledge.” Unfortunately, as Richard quickly pointed out, I was at the time unable to flesh out this criticism with all the detail that such a claim merited. In this post I would like to clearly illustrate the two usages of the word “to know” involved in Jackson’s argument as well as provide an argument in support of the assertion that Jackson’s argument against physicalism actually depends on a single usage of the word.

As a recap, Jackson’s knowledge argument is illustrated with the case of Mary the color scientist who is kept from experiencing any colors herself until her release. Jackson’s argument is as follows:

1. “Mary (before her release) knows everything physical there is to know about other people.


2. “Mary (before her release) does not know everything there is to know about other people (because she learns something about them on her release).


3. “There are truths about other people (and herself) which escape the physicalist story.”

Last time I somewhat misleadingly called the two kinds of knowledge which were being conflated “know that” and “know how” which were supposed to be roughly associated with knowledge gained by third person observation of a causal system and knowledge gained by actually being a part of the causal system itself. While I stand by my assertion that no amount of third person knowledge of a causal system can ever amount to actually being or having been a part of the causal system itself, my use of the “know that”/”know how” distinction wasn’t quite right.

Rather than “knowledge that” as a label for the third person observation of a causal system, I will adopt the new label “propositional knowledge.” This is knowledge which can be called justified true belief. The label which I want to give to the first person participation in a causal system is “experiential knowledge.” It is my contention that this latter type of knowledge is not propositional in its nature, and as such involves nothing which could be considered a belief.

Accordingly, it makes no sense to judge experiential knowledge to be justified or not since it is not propositional in nature. Experiential knowledge can be neither true nor false, and as such does not constitute truths, falsehoods or facts. Clearly, Jackson’s (3) requires that the knowledge which Mary gains upon release contains truths of one kind or another, but this is exactly what a failure to distinguish propositional knowledge from experiential knowledge prevents one from recognizing.

Let us now present a variation on Jackson’s argument:

1’. Mary (before her release) has all propositional knowledge there is to have about other people’s experience of color.
2’. Mary (before her release) does not have all experiential knowledge there is to have about other people’s experience of color (because she gains experiential knowledge upon her release).
3’. There are no truths about other people’s experience of color which escape Mary before her release.

Now of course at this point every dualist will be cringing at the liberties which I have taken with Jackson’s argument. There are a number of areas which must be laid out in far greater detail. First, my argument requires that much of the propositional knowledge which is gained by Mary is non-physical in its nature, thus making my argument entirely beside the point. Second, can we really be sure that no propositional knowledge will be gained upon Mary’s release?

In order to approach the first concern, we must remember that Jackson’s argument is that physicalism cannot be true. Accordingly, my reply to Jackson’s argument is not intended to be an argument for physicalism so much as an argument that physicalism can possibly be true. Consequently, we can be allowed to operate under the assumption that physicalism is in fact true and that mental states are in fact identical to physical states.

In other words, assuming the truth of physicalism, Mary does indeed get to have access to all information regarding other people’s experience of color, including verbal reports. Indeed, assuming physicalism to be true, Jackson’s story would actually require that Mary have access to such reports in order for her to have a complete propositional knowledge of other people’s experience of color. Thus, Mary would indeed know what the experience of color was like in so far as such knowledge can be put in propositional form.

We are now in a position to address the second concern that, as Richard pointed out, “It seems intuitively clear that Mary learns a new fact, namely, what it is like to experience red. She learns that redness looks a certain way.” My response is that inasmuch as there are facts which can be learned, Mary could have learned them while still in captivity by some other medium. Truths and facts can only come in propositional form, and as such could have been delivered to Mary prior to her release.

This is not to say that she doesn’t learn anything upon her release. Instead, what she learns upon her release does not consist in any new facts or truths, only experiences. Again, this is not an argument in favor of physicalism, but should only be read as a criticism of Jackson’s arguments against physicalism. He claims that physicalism cannot be true since new facts or truths are learned upon Mary’s release, and this is simply not necessarily the case.

It can still be argued, however, that nature of these propositions which describe what red is like would be meaningless to Mary while she had still never experienced red. This however is just as much a problem for Jackson as it is for my account. It is simply too easy to rely upon common intuition which suggests that Mary is learning new facts about “what red is like.” But what is red like? What is the fact of the matter? My position is that inasmuch as there is actually a fact of the matter, it can be learned by Mary while in captivity and inasmuch as there is not a fact of the matter then Jackson’s argument fails.

It is also tempting to respond by pointing out that a statements being meaningless to a person does not make the statement any less true or factual. However this line of thought would take us far from the topic at hand. Suffice it to say that even if propositional knowledge requires experiential knowledge for it to count as knowledge in any meaningful sense of the word, this does not entail that there is no difference between the two types of knowledge. It is this difference which is the important point which Jackson’s argument does not take into account.

(As a completely off-topic side note, it is a machines total lack of experiential knowledge which makes its syntactical manipulation of symbols completely lacking in semantic content. A computer can output statements about red all day, but these statements will never mean the same thing to the machine as it does to those of us who are not locked in Mary’s cell. Indeed, it is precisely because those outputs do mean something to us that we are willing to wrongfully attribute intelligence or consciousness to such a machine, and this is primary shortcoming of the Turing Test.)

Update:

In response to Richard's thoughtful comment below, I have had to slightly modify my position a bit. The modified position can be found here.