Have you ever thought about how can we know that the red color in my mind is the same red color that is in your mind when we see the same image?
Early 20th-century Austrian-British philosopher Ludwig Wittgenstein has proposed the following thought experiment: Consider a group of people in a room, each of them holds a box. Only the person who holds the box can see what is inside their own box, while no one can peek into other peoples’ boxes. All of the people refer to what is inside their box as a “beetle”. When I say something is a “beetle”, it is me comparing what I see around the room to the “beetle” in my box, and when you say something is “beetle”, it is you comparing what you see around the room to the “beetle” in your box. But how can I know what is in my box is the same as what is in your box? Wittgenstein said it is unknowable. Language is private, and we can never perfectly communicate our subjective experience, only provide some analogies using language. I can not show you what is exactly inside my box, but I can point to your things in the world that I think is similar to what is inside my box. I can not make you feel what I feel, but I can describe what has happened to me, or when you see the laughs or tears of mine, you would use the time you laughed or cried as a proxy for understanding my feeling at the moment.
Empathy is to try to imagine how others have felt by putting ourselves in their situation. But it is difficult to empathize with others when we lack subjective experience. I can read about the people living in poverty, their living conditions, but is reading about it sufficient for me to feel the struggle and hardship they are experiencing? There are an estimated 2.5 billion people lack access to improved sanitation. This is more than 35% of the world’s population. But it is difficult for me to empathize with them because as long as I can remember, I have always been able to turn on the faucet and clean water would come out of it. But I do not think our lack of subjective experience is an excuse for not trying to understand. I may never fully know what is the beetle that is inside your box, but with efforts, I can get a better and better picture of it. Even though it is not perfect, language can help to make my thoughts and feelings as transparent to you as possible, to bridge the gap between our understandings, and to make us feel less alone in a world in which we can never show others our own subjective experiences.
If we can never peek into other people’s subjective experience, how do we ever manage to understand each other at all? Let’s get back to the example of the colors. How can I communicate the color red to you and know that you agree with me in the meaning of the word “red”? Consider the following experiment, you sit in front of a monitor, it will show you one pure color patch at a time, if you consider the color shown as red, you will answer yes, otherwise you will answer no. There is another participant, at the same time, is given the same color patch and asked the same question. In this experiment, if for every color patch, you and the other participant’s answers always match, then we can conclude you two agree on what is red. This test is completely behavioral, that is based on what is observable, i.e. our answers, it does not matter how I know the color is red, or how the color red makes me feel, as long as the participants give the same answers, they agree on the meaning of the word. Then when you ask the other participant to pick out a red object from a pile, they will pick the object with the color that you consider as red because the two of you agree on the concept of red.
Now consider the following thought experiment: Imagine there is a girl name Denise with an extremely rare condition, in her mind the color red and green are switched. That is, when she sees an object of the color red, she would see what you consider as green in her mind, and when she sees an object of the color green, she would see what you consider as red. But she had this condition ever since she was a baby before she learned the language. When her parents taught her color, they pointed to her what they thought as red objects and taught her the concept of red. Now she has associated the word “red” with her perception of green. When you ask her what the color is of a red object, even though she perceived it as green in her mind, but because she has associated the sense of green with the word “red” from the very beginning when she started to learn the language, she will still answer you that the object is “red”. And there is no way for us to figure out she sees the color red as we see the color green because whenever we ask her what the color is of a given object, she always gives us the word that we expect.
There is a common conception that linguistic understanding is an activity of the mind that is unique to humans. But in fact, linguistic understanding is a measurable behavior. In a way, we can view language as a measurement we perform based on our sensory experience. When I see the color red and say “It is red”, I am converting my visual perception to a string of symbols. And this is not unique to humans. In research conducted by Doctor Ramirez, dogs were trained to count, even though they don’t write or speak the human language. What the researchers did was that they have a white tray in which they will put a number of different small objects. Then several whiteboards were presented to the dogs, each one with a different number of dots. The dogs were trained to pick out the whiteboard with the same number of dots as the number of small objects in the tray. The trained dogs can consistently select the correct whiteboard based on the number of objects in the tray, that is, they understand the concepts of numbers, even though they do not know the symbols we use for numbers. Similarly, chimpanzees can be trained to use sign language for different objects. When asked what object they saw, they can consistently associate the same sign with the same objects. So they also have linguistic understandings.
Now, in the color experiment above, I have said that if you and the other participant always agree on if a given color patch is red or not, then we may conclude that you two agree on the concept of red. But you have not seen the other participant in person, what if the other percipient instead of being a human is actually an artificial intelligence, do you two still agrees on the concept of red? Does the artificial intelligence understand what you mean by the word “red”? I think it does. Even if a human perceives red as green and green as red, as long as they pass the linguistic agreement test, then you two agree on the concept, and there is no way for us to know if the colors in other people’s minds are scrambled. Similarly, it doesn’t matter how machines perceive color or process words, as long as they pass the linguist agreement tests, they understand the linguistic concept just as we do.
It is a common conception that understanding and intelligence are uniquely human traits. To have intelligence is to think like a human, whatever that means. We know that computers can do multiplications, but we don’t think that computers understand the intuition of multiplication, because we often associate understanding with the Eureka moment and the feeling of something in our minds suddenly clicked. But that is a mistake. Sudden epiphany has very little to do with real understanding, and the feeling of understanding something is not the same as actually understanding it. There are plenty of times in college when I thought I understood some concepts, only to find out later when I made horrible mistakes in tests. How do we know we understand something then? Well, we need to pass the linguist agreement test on that subject. How do we know a student knows how to do multiplication? We throw a bunch of multiplication questions at them and see if they would get the same answers as ours. If they did, they understood multiplications. If when a human passed the test, we consider that they understand the concept of multiplication, we should also fairly consider a computer that can pass the same test also understands the concept of multiplication. If we think computers can not understand multiplication even if they have passed the same test we used for humans, just because they are not humans, it is a bit prejudiced, isn’t it?
Now if we define understanding a concept as passing the linguistic agreement test, then the only concepts that can be understood are the ones that can be defined without logical contradiction. Take the concept of multiplication as an example. We can test someone’s understanding of multiplication using a linguistic agreement test. Because when given two numbers there is an unambiguously correct product of the two numbers, then anyone, whether a human or a machine that really understands multiplication, should give that answer. If someone tells me that 3 times 3 is equal to 7 in a decimal system, I can say that they do not understand multiplication, even if they feel that they do. So, how about non-mathematical concepts, such as freedom or justice. Given a policy, we all probably have some opinion about whether it hinders or promotes freedom. We can use this as the linguistic agreement test for the concept of freedom. Each participant will be given a policy and its intended goal, and answer if they consider the given policy is good for freedom or bad. For anyone who ever had a debate on politics, they would understand there is no chance freedom can pass this test, at least not in our current society. This is largely because freedom means different things to different people at different times. To revisit the example I have used in the last episode, if we consider freedom as not to be owned by other human beings, then the emancipation of the slaves is good for freedom. But if we define freedom as a market free of government regulation, then emancipation is infringing on the free market. The problem is, to many people, freedom means both. As the two definitions are conflicting, for any policy, we can just pick and choose which definition we want to apply, and get different conclusions. This makes the answer to the question completely arbitrary and subjective. In such a case, I am not sure what it means to understand an inherently inconsistent concept.
So, how do words gain their meaning? The English word chicken in Spanish is pollo, or in Chinese is 鸡. The same concepts can be associated with different symbols in different languages, and there is no law of nature to dictate that the 7 letters chicken have to mean the feathery beasts that are the descendants of the dinosaurs. How did the symbols get the meaning they are now associated with?
Wittgenstein said: word is use. When a word is being used to refer to a certain object, and other people in the same community have also started to use the same word to refer to the same object, the word gained its meaning as a reference to that object in its linguistic community. This process can be called definition by reference. It is how we learn most of the words. We learned the concepts of cats by given many many different references of cats, pictures, videos, and drawings. Many philosophers have debated whether universal concepts exist. Of course, whoever has played with a cat would agree a reference of a specific cat does exist, as they touched the cat, felt its fur, and maybe even being scratched by it. What the philosophers have debated is that if there exists a perfect cat, that is the Plutonic idea of all cats. Some philosophers believed that when we are determining something is a cat or not, we are, in our mind comparing the thing we see and touch to the Plutonic idea of cats, and if what we see and touch feels close enough to the perfect cat in our mind, then we say it is a cat, otherwise, we say it is not. For each of the concepts, such as cats, dogs, multiplications, or freedom, is there a Plutonic idea of the concept that we can all agree on? This turns out to be a far trickier question.
One of the earliest recorded dialogue of this problem is called the Sorites Paradox or the paradox of the heap, attributed to Eubulides of Miletus. Consider a heap of 1 million sand grains, we remove a single grain, it is still visibly a heap. Then if we remove a single grain again, it is still visibly a heap. When we continually removing the grains, one by one, until there is only one grain left, is it still a heap? If not, when exactly does it stop being a heap? Where that line lies is different from people to people and deeply dependent on what references we used to learn such concepts. If when learning the concept of the heap, larger piles of grains were used as a reference, the person would more likely draw the line earlier than someone who learned the concept of the heap with smaller piles. When defined by reference, the meanings of words become subjective to each person’s experience as each of us has a different set of examples we use to learn each word.
Here is another example, the color turquoise, if you are interested to look it up, the hex number of the color is #0D98BA. The color is between blue and green. But if you ask someone to put it into either the category of blue or the category of green, you will find something interesting. People who grow up in the western culture are more likely to categorize it as blue, while someone who is from the eastern culture is more likely to categorize it as green. That is, even though in both cultures, there are concepts of both blue and green, the ranges of the colors are different from culture to culture. Furthermore, what we consider as essential to a concept may also vary. For example, to some people, one of the essential properties of cats is their fur, and they would have a difficult time accepting that a hairless cat is a real cat. Here is another example from my personal experience, where I was growing up, all the popcorns served are coated with sugar or honey. So for me, one of the essential properties of popcorns is its sweetness, and I was and still is having a hard time accepting the salty snack served in the American theatres are popcorns, even though, you know, they are popped corns.
This phenomenon has illustrated the difference between, what Wittgenstein called, references and senses. References are the physical things we referred to in our language, but senses are what the physical objects make us feel, from our sensory experience of petting a kitten to our emotional response of having a warm meal after a long and exhausting day. Different people, when looking at the same references may have completely different senses. One obvious example is two people looking at the same rainbow, one of them is color blind. Even though they are seeing the same object, their senses are different as they would see different colors. But it is not just the different sensory responses that may result in different senses, our personal experience can also lead to different senses. If when you were growing up, every year you went to your grandma’s for Christmas, and she would bake fresh gingerbread cookies for you. When you share your gingerbread cookie with your friend who has never celebrated Christmas before, even though you two are sharing the same cookie, what the cookie means to each of you would be completely different for you two. It might bring you back to the time when you were a kid and running around in the living room next to the Christmas tree, but to your friend, it is just a weird flavored cookie.
In our daily conversation with friends and family, we rarely try only to communicate raw facts, what we usually want, is to share what we feel and think to those who are close to us. But our feelings are just like the beetles in the box, I can tell my friend that I am happy, angry, or sad in words, but there is no way for me to directly share to them what I am feeling at this exact moment, the best I can do is to share the events that have made feel how I feel, and hope that with empathy, my friend would feel the same as I did in the same circumstances. That’s why we share our gingerbread cookies with our friends, go watch movies together, we hope that with the shared experiences, we also would share senses. And it works more or less for people who grow up in a similar culture. If it is the cultural norm to spending holidays at grandma’s eating gingerbread cookies, sharing the gingerbread cookie with your friend is likely to remind both of you of the time spent with your families. But such expectation can also become an empathy barrier for those coming from a different culture, if the gingerbread cookie reminded you and all of your friends of the good times with family, when someone from a different culture dislikes gingerbread cookies, it could be easy to identify them as weird and other, if we hold the belief, either implicitly or explicitly, that all should feel the same in response to the same experience.
Even though we can not directly share our subjective senses, we can still use expressions, words, and body language to illustrate them. Others can not directly feel the joy I feel. To me, the reference to the word joy is how I felt internally, but to others, it is what they see and hear: the smile on my face, the excitement in my voice, and my dancing feet. And this differs from culture to culture, in a more conservatives culture, a smile may be all that people show when they are ecstatic, while for a more outgoing culture, it may be acceptable if not common to go around and hug everyone when they are happy. There are different cultural expectations about how to show that you are happy, even though the two people may be feeling the same amount of happiness, the perceivers may read them differently based on their cultural expectations. If I expect others to show excitement by jumping up and down, I might jump to the wrong conclusion about how happy someone feels when they are coming from a more conservatives culture. One of the great wonders of humans is our ability to use language. We have invented ways to share our thoughts and feelings that others can not directly observe. But we should also be careful not to jump to conclusions about other people’s feelings and intentions, because the only one who know how they really feel, is the person who is experiencing it.
This definition by example is pretty useful when words are references to a physical object that we can point to using our fingers. But it comes up a bit short for words that are defined by relationships. Take the word “father” for instance, to learn the concept of the father, we can show a picture of two persons an older male and a younger person. The concept of “father” is not defined in isolation but as a relationship pair. Two-person can be labeled one as a “father” and the other as a “child” if the relationship between the two resemble what we consider as a father-child dynamic. So the word “father” does not refer to a specific entity, but the label we give the one side of a relationship, and “father” and “child” have to exist together, there is no father without a child and no child without a father.
In the next episode, I will continue the discussion of the definition by relationship, and I will try to answer the question: is mathematics invented or discovered? I will also answer a question that has troubled philosophers since Plato: what are exactly numbers. Stay tuned!
Before I end this episode I want to challenge the listener to take some time to think about the words we use. What does it mean to be fair, just, or equal? And to not only try to make sense to ourselves, but also try to understand what do those words mean to others, and keep in mind, the same words can mean different things to different people, and language is here to help us to make our thoughts and ideas transparent to each other. So let us try to understand others, even if we may not agree with them.
RhaPsoDySea 