The Knowledge Argument
In the Philosophical Quarterly of April 1982, Frank Jackson released one of the most famous studies in epistemology (the study of knowledge) and anti-physicalist articles: “Epiphenomenal Qualia”. It seems to provide evidence for something Jackson calls “Qualia”, which he does through this argument, termed the “Knowledge Argument”, presented in premise and conclusion form below:
P1: Prior to experiencing thing X, person Y knew everything that could be described in the language of science about thing X.
P2: Upon experiencing thing X, person Y learns something new.
P3: What Y comes to know is that experiencing X includes a feature not describable in the language of science, that is, what it is like to experience X.
Conclusion: Science is unable to describe all aspects of reality.
Before looking into this argument further, there are a few things here that need to be clarified and defined in preparation for future discussion on this topic.
Let me first define what a “fully complete description” entails. A “fully complete description” is a description of something so complete that no other possibilities are possible other than the description provided. If there is some way to provide an alternative to a fully complete description, then the description is not fully complete.
Let me also define what it means for something to be “that there is something it is like to be them”, or “that there is nothing it is like to be them”. In the former case, it is like being them when we can imagine ourselves being them, while in the latter case, it is nigh impossible for us to even imagine ourselves in the place of “them”. For example, we can imagine ourselves in the place of another human, or perhaps even a dog. However, we can’t exactly imagine ourselves as a table or a leaf.
What does Jackson mean exactly when he says that person Y comes to learn something? The “something” here is not something that could be learned through countless hours of studying or testing oneself, or so Jackson claims, instead, what Y learns is the experience of X, qualia.
Jackson’s point is this: no matter what kind of technical skills and knowledge one has about something, the experience of that thing is unable to be replicated by just reading about it or studying it in some other way without actually being exposed to and being able to experience it. The natural sciences are not able to provide a fully complete description of our universe.
What Mary didn’t know
Jackson illustrates his point with the following example, which I have paraphrased:
“Mary is a brilliant scientist who is forced to investigate the world from a black-and-white room via a black-and-white computer screen. She specializes in the neurophysiology of vision and acquires physical information about what goes on when we see ripe tomatoes, and the sky, and uses terms like “red”, “blue”, etc. She discovers, for example, which wavelength combinations from the sky stimulate the retina and how this produces the contraction of the vocal cords and expulsion of air from the lungs that result in the uttering of the sentence “The sky is blue”. When Mary is released from her black and white room or is brought a red apple, she will learn something about the world and our visual experience of it?”
According to Jackson, Mary would indeed come to learn something new — the experience of seeing the color red. If we were to term the state of the brain when it sees the color red “Brain State R”, even though Mary may understand the location of every single neutron that is activated while in “Brain State R”, she is unable to put herself in such a brain state on command. We cannot even simulate the experiences we have had in the past (try to make yourself feel pain right now); how can we expect Mary to be able to simulate the experience of something that she has never experienced before?
The Modal Argument
Jackson also included another argument with his paper, the Modal Argument. This argument was not an original invention by Jackson but was instead used by past anti-physicalists as well. It can be presented as follows in premise and conclusion form:
P1: We can imagine a world with exactly the same parameters as ours, in every way describable with the language of science except for one. In this world, it is like nothing to experience X.
P2: Since such a world is imaginable, it is conceivable that such a world could exist.
P3: If two possible worlds are different, they must have different features.
Conclusion: Science does not give a fully complete description of the world.
To illustrate this example in a more concrete way, take this example. Let us first imagine a world that is identical to our world in every possible way, except for the fact that in this world, it is physically impossible for these people to see red, i.e., to them, it is like nothing to see red. We can also see that since such a world can be thought of, it has a chance of existing, and since there is obviously a difference in a feature not described in the natural sciences (one thinks that the experience of seeing red is something, while the other thinks that it's nothing), we can conclude that the two worlds are differentiated in that way.
Objections to Jackson’s claims
Now that I have finished giving an overview of Jackson’s points, let me begin to raise objections to his claims. This will be done in two sections: first an objection to his idea of the knowledge argument, then an objection to the modal argument.
Objections to the Knowledge Argument
Scientific Knowledge Counterargument: The first premise of the argument states that prior to experiencing thing X, person Y knew everything that could be described in the language of science about thing X. However, it is simply not possible that this to be true. When performing any sort of scientific observations and collecting data, one must not only gather quantitative, but also qualitative data. If we are collecting data on some kind of a chemical reaction, we must not only observe what chemicals change into what other chemicals, i.e. what kind of objective physics is going on, but we also observe things like how it smells like some other thing or that it looks like something else, i.e. what kind of subjective things we are observing. If Y is unable to experience X and thus unable to make qualitative observations, it renders the claim that Y knows everything about X invalid.
The Circularity of Knowledge Counterargument: In order for X to know that the experience of X and the knowledge about X are not the same things, “knowing” here has to satisfy the conditions of knowledge that were mentioned earlier in the course, but I have included a copy of the conditions below.
To know that P, it must be the case that:
P is true.
You are sure that P is true.
You are justified in being sure that P is true.
You are sensitive to P, ie. if P were not to be true, you would not believe that P is true.
You are generally correct in matters relating to P.
You come to know P by reliable means.
As we can see, the claim mentioned above already violates the first rule, as there is no way to know that the experience of X and the knowledge about X are not the same things without assuming that it is true. By upholding the third premise of the argument, we must either accept the circularity of the argument or assert dogmatically that the premise is true.
Identity Theory: What this theory states can be summarized in the structure below.
Let “X” mean: The way it feels to see red
Let “ X*” mean: The way that the brain is when seeing red (describable with the language of science)
Since X=X*, we can conclude that qualia (or the experience of something) can be described in physical terms.
We can see that X does in fact equal X*, as X* is the definition of the state of the mind while X is true, or put another way, if the brain is in the state that brains go into when they perceive red, then we are perceiving red.
A common response to this argument is to ask, "If this statement were to be true, then how do we explain our feeling of surprise or shock upon first witnessing X?” This objection can be explained by the idea that there are different ways of knowing.
Take the following example:
“John and William were in a spaceship together, which, when docking, accidentally crashed into the space station they were trying to dock onto. Fortunately, both John and William survive and are placed in the medical wing of the space station. After regaining consciousness, John picks up the most recent edition of the newspaper and reads that “two people, John, an engineer, and William, a stockbroker, had been fatally wounded during the crash, both having lost their memories. Despite this, they both managed to survive and are currently being hostilized on the space station.”
If we were to ask John right now whether John is an engineer, he would reply that John is an engineer. However, if we were to ask him if he was an engineer, he would not be so sure.
At this moment, if John were to think about whether he was an engineer, he would at the same time have no idea and, in a way, know confidently that he is an engineer.
To conclude and summarize, X does not, in fact, learn something new but actually learns something that they already knew in a new way.
Objections to the Modal Argument
The Imaginability/Conceivability Paradox: In the second premise of the Modal Argument, it states that if it is possible for us to imagine what a world could be like, such a world could exist. Why this could be accepted as true or even possible seems to defy reason. Just because we are able to imagine some object that moves at the speed of light does not necessarily make something like that possible. If we were to say that such a thing really could exist, then there is no use in making the claim in the first place, as our world and that world would be so different that comparing them would be like comparing an apple with an orange. To accept the argument is to invalidate the same argument in this context.
Modal Paradox: If we were to modify the first premise, we could get the following result. We can imagine a world just like ours with respect to features describable in the language of the natural sciences, but in which no one is able to make accurate assumptions about the nature of their world, including making accurate assumptions about worlds just like theirs with respect to features describable in the language of the natural sciences. Now, we are unable to make any assumptions with confidence about the nature of the existence of other worlds where everything is the same or even the color red. The assumptions and claims of the first premise are incongruent with themselves.
Conclusion
In summary, while the points against anti-physicalism and ones for physicalism are numerous, I was only able to include what I deemed the most essential or fundamental point The points I presented are summarized as follows:
Scientific Knowledge Counterargument: How can we truly gain a complete understanding of a subject without both quantitative and qualitative observations? By denying X the ability to make qualitative observations of Y, he does not truly have complete knowledge about Y.
The Circularity of Knowledge Counterargument: The claim that the experience of X and the knowledge about X are not the same thing is a dogmatic one and cannot be proven to be true, negating premise three.
Identity Theory: Since the experience of something is the same thing as the brain state someone would enter if they were to experience that thing, the experience of something can be known as a physical matter. This proves premise two to be false.
The Imaginability/Conceivability Paradox: Being able to imagine something does not mean that that thing could actually exist; if the statement above were false, it would be an unsubstantial comparison between the imagined thing and the real thing.
Modal Paradox: If we were to say that the world that we imagined disallows people to imagine worlds that disallow the imagining of further worlds, we would fall into a paradox, as we could be one of the paradoxical worlds disallowing ourselves from imagining such a world in the first place, disproving the first premise.
Footnote
While I am agnostic when it comes to topics like this, I nonetheless found this argument to be one of the most interesting ones. Ultimately, I do not think that this debate will, in due course, be resolved. Ideas like knowledge, the justifications for knowledge, the definitions of knowledge, how we obtain knowledge, and how to categorize knowledge are all cosmological questions posed to the individual. These topics are all greatly personal and cannot truly be communicated with one another to any degree of satisfaction or meaningfulness.