Mary's Room: How To Really Make Sense Of Knowledge? - A white-board style graphic illustration showing a black and white room with a couch, chair, lamp and computer screen inside it. Also inside this room is a happy stick figure. Pink signs label the room as Mary's room and the stick figure as Mary.

Mary’s room is a philosophical thought experiment that tries to understand the fundamental notion of human knowledge. Frank Jackson, an Australian philosopher and professor, originally proposed the thought experiment in 1982 in his work Epiphenomenal Qualia.

In the world of philosophy, this thought experiment became famous for its divisive nature. Various philosophers of different backgrounds and ages have engaged in active discussions and arguments around this topic. This just goes to show how divided we are (as human beings) about what “knowledge” means to each of us.

In this essay, I will go over Jackson’s core argument using Mary’s room. To make the thought experiment contemporary and avoid potential misinterpretation, I will be modifying the thought experiment. In essence, I will be presenting my own version of Jackson’s thought experiment.

By the end of this essay, you would ideally be able to appreciate the complexity of the problem of knowledge and how it finds applications in the field of artificial intelligence and other future technologies. Let us begin.

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Mary’s Room

The thought experiment begins with a fictitious super-human being called Mary. You see, ever since she was born, Mary grew up all alone in a special room. The speciality about this room is that it causes a colour blindness in its occupants such that they are only able to see black and white.

As a baby, Mary opened her eyes for the first time inside this room and has never left it for the past 25 years. I know how terrible that sounds. But I promise that it gets better from here. The other specialty about this room is that it comes equipped with the entire literary knowledge of the universe that is known to man.

Mary’s Room: How To Really Make Sense Of Knowledge? — A white-board style graphic illustration showing a black and white room with a couch, chair, lamp and computer screen inside it. Also inside this room is a happy stick figure. Pink signs label the room as Mary’s room and the stick figure as Mary.
Mary’s room — Illustrative art created by the author

Now, we turn our attention to Mary. The reason we consider her super-human is for her special cognitive capabilities. She can consume, process, and store extraordinary amounts of knowledge in her brain.

In fact, over the past 25 years, she has managed to learn everything that is known to man! In this thought experiment, however, we are concerned with knowledge of a specific field: chromatic vision.

Mary’s Experience

As Mary lives inside this dull and dreary black and white room, she sees everything in black and white. Her books, computer screen, plates, tables, and everything else inside that room feature only two colours: black and white.

Even though she has never experienced colour vision, Mary knows everything about how colour vision works. For instance, she knows how human beings possess special receptors in the eyes that can differentiate between three different wavelengths of light: red, blue, and green.

She also knows how these receptors send electrical signals to the brain and the brain processes colour images. In short, she has all possible human knowledge about colours and colour vision.

Mary’s Room: How To Really Make Sense Of Knowledge? — A white-board style graphic illustration showing the stick figure (Mary) on the left being positively surprised by seeing a red apple towards her right.
Mary and the apple — Illustrative art created by the author

One fine day, the door to the room opens, and Mary realises that there is an entire world outside the room. Naturally curious, she slowly and cautiously steps outside. As she steps outside, she sees an apple placed on a plate on the floor. The floor is black, the plate is white, and the apple is bright red in colour. Given these conditions, the thought experiment poses the following questions:

1. Does Mary learn something new about colours the moment she experiences colour vision for the first time?

2. Or does the fact that she already possesses all human knowledge about colours and colour vision mean that she learns nothing new from this experience?

What is your take on this? I am pretty sure that you have an opinion. For now, just hold that thought at the back of your head. We will return to your thoughts eventually.

Epiphenomenalism

Jackson originally proposed that his thought experiment demonstrated the existence of special entities known as “Qualia”. They are qualitative non-physical elements of knowledge that one attains only via experience and not prior knowledge from books, etc.

He suggested that one can achieve complete knowledge only if one has access to physical knowledge as well as non-physical qualia. In simpler terms, according to Jackson, knowledge from physical sources such as books can never fully replace knowledge gained from experience.

According to this argument, Mary can know everything about the colour red from her vast library of literature about physical phenomena in the universe, but she learns something new when she experiences colour vision for the first time.

Within the philosophical circles, this stance came to be known as epiphenomenalism.

Physicalism

In opposition to Jackson’s stance were the physicalists. According to these folks, all knowledge can be conveyed by physical entities. Even emotions associated with new experiences can be recreated by reproducing the corresponding neuron impulses and causing the consequent hormonal responses, etc.

As long as Mary possessed the knowledge of how physical processes are associated with mental states, Mary would be able to “simulate” experiences of colour vision in her mind. Thus, when she actually experiences colour vision for the first time, she would be experiencing nothing new.

Consequently, she would not be learning any new knowledge. This point of view aligns with how computer theorists model information using bits. In fact, the whole venture of artificial intelligence (AI) aims (among other things) for this goal.

We will come back to this point in a bit, but for now, let us focus on one more interesting take on this problem.

Dualism

It would be boring if the responses to Mary’s room were simply black and white (did you see what I did there?). So, the dualists are here to save the day.

There are numerous takes under dualism that we could discuss the topic forever. I will just go over one of the dualist takes that I found appealing, so that it gives you a rough picture of how things work here.

Some dualists consider that all of knowledge is indeed physical (the physicalist stance) and qualia are special physical knowledge entities that are bound to only experience. So, one can obtain qualia-knowledge only through experiences. If this is too abstract for you, let us turn back to Mary.

Mary indeed possesses all possible literary knowledge about colours and colour vision. But still, the dualists argue that there is some physical knowledge missing in literature that only the experience of seeing colours for the first time can convey.

And this experience-bound physical knowledge is what they refer to as qualia. Some physicalists argue that this dualist argument is actually a physicalist argument.

As you can expect, there are diverse takes on the same topic. What does this mean for us all and what can we actually learn about knowledge from this thought experiment?

Mary’s Room — How to Really Make Sense of Knowledge?

If you think about it, Mary is a proxy for humanity as a species, Mary’s room is a proxy for human scientific knowledge, and Mary’s experience is a proxy for conscious experience. So, this thought experiment is trying to solve a much more general problem:

1. Can conscious experience be recreated using physical information?

2. Can mental states be completely represented by physical processes?

One of the fields that is directly linked to these questions is artificial intelligence. If it is indeed possible to model mental states using physical processes, we should eventually be able to recreate consciousness using artificial intelligence.

Some AI researchers who closely work with neural networks suggest that we might be able to create something physically analogous to our own brain and other intelligent physical systems. But we might never be able to understand how these systems work at a fundamental level.

In short, it could be that we might be able to create some form of consciousness without actually never being able to understand how it works in the first place. If this situation really does come true, can we really claim that we have understood human conscience?

Author’s Take on Mary’s Room and the Problem of Knowledge

I tend to side with the physicalist take on knowledge. Based on my life experiences, I see increasingly more evidence that every human experience can be reproduced using physical processes.

Mary’s Room: How To Really Make Sense Of Knowledge? — A white-board style graphic illustration showing the stick figure (Mary) on the left being positively surprised by seeing a red apple towards her right.
Mary and the apple — Illustrative art created by the author

Let us assume that Mary is “surprised” when she experiences colour vision for the first time. I would suggest that what is actually happening here is something known in mathematical circles as “coordinate transformation”.

During her experience, Mary is accessing the same knowledge she knows using a different medium. This, in itself, gives her new knowledge. If this is confusing, consider the following example:

1. You first enjoy a sunset view in front of a lake.

2. Then, you ask your tall and burly friend to hold you upside down. Now, you enjoy the same sunset view in front of the same lake, but your view is upside down.

During your second experience (when you are upside down), you are accessing the same knowledge/information using a new perspective. And this perspective offers you new knowledge that tells you how the scenery looks upside down (the perspective provides knowledge about itself).

Mary’s Room: How To Really Make Sense Of Knowledge? — A white-board style graphic illustration showing the same black and white Mary’s room from before, but this time, the entire room and its contents, including Mary are upside down. The pink markings labelling Mary’s room and Mary are still upright and easy to read.
Mary’s room upside down — Illustrative art created by the author

Similarly, as far as experience is concerned, there could be infinite coordinate systems that literally make physical knowledge an infinite venture. The answer is not clear. This is best illustrated by the fact that Jackson, the guy who proposed the thought experiment, reversed his view and took the physicalist stance later in his life.

Long story short, what I am trying to say is that Mary’s room just reveals to us the limits of human knowledge.

With rapidly advancing fields such as theoretical physics and artificial intelligence, we are pushing our own limits every single day. Who knows what we are capable of achieving as a species? We are indeed living during fascinating times!

Your Turn

Do you remember when I told you to hold your take on this problem at the back of your mind?

Well, now it is your turn to express what you think about this thought experiment. Feel free to do so in the comments section.

Reference: Frank Jackson.

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