Twelve Lessons in Philosophy Descartes’ Skepticism

Another major inspiration from Descartes’ philosophy: skepticism.

Not knowing what is true, one can therefore doubt everything - the root of skepticism.

In the 16th and 17th centuries, people found that neither tradition nor authority was reliable. There is no America in the Bible, and astronomy and geography prove that the earth is not the center of the universe. This is an era in which the worldview is falling apart. People want to find a truth that explains the world, but they don't have that ability, and they can't trust previous authorities. So what should we believe? Human beings are beginning to look for new theories to choose to believe. At this time, Descartes proposed the idea of ??not trusting authority, not trusting past traditions, and not trusting anything else. Because we don’t know what to believe, we can doubt everything.

We can believe that the objective world exists, or we can suspect that we are fish living in a goldfish bowl. The world we see is distorted and not real. We can even think that we are living in an illusion. It's all a dream. Our senses can be manipulated and we have no way of knowing if we are living in a hallucination. Just like when we read martial arts novels, we can easily pretend to be the male protagonist, with unparalleled martial arts skills, pleasure and revenge. That pleasure is an important reason that motivates us to continue reading. Our brains are easily deceived. But the foundation of all thoughts must have its true core, including thorough skepticism.

Everything can be doubted, but there is no doubt that I am doubting. No matter what I doubt, it cannot deny the existence of the objective fact that I am doubting it. This is the only view that Descartes discovered that is solid and can stand any test, and I am doubting it.

The subject I am doubting is me, I am doubting. Descartes uttered the famous saying that is well known to everyone and plays an important role in the history of philosophy: I think, therefore I am. Doubt is a kind of thinking, so my thinking must exist. Descartes is the person who compiled a complete philosophical system after ancient Greece and is known as the father of modern philosophy.

The dispute and skepticism between monism and dualism opened people's eyes, but it does not mean that he came up with the correct answer, but it guided us to continue to think and deepen the answer in the hundreds of years after him. , the understanding of the universe is also constantly deepening.

Descartes raised skepticism, but his answer was limited. His cognition and ability only allowed him to answer part of the questions. Just like I think, therefore I am, then if I don't think, am I not there? He released the skeptic monster from its cage, but he could not put it back. After so many years of development, our understanding of skepticism has been very profound. Now there are two main systems of skepticism. Now we will focus on one of them, the torture of the senses: parallel skepticism.

Torturing the senses and questioning, what is the crux of parallel skepticism?

Descartes believed that the reason why I doubt my knowledge is because the way to obtain knowledge is unreliable. We understand the external world through our own sensory system. We have five basic senses: eyes, ears, nose, tongue, and body, corresponding to color, sound, smell, taste, and touch. So are our senses reliable? They are not. Is what we see real? Not necessarily. The senses are the reaction of the brain, just like when I was sleeping in bed and in a daze, I saw a basketball flying over, and subconsciously went to catch the ball, but when I hit the wall, I woke up in pain and realized that it was an illusion and a dream. We run in dreams and fly in dreams, but is it really? Obviously not, dreams are just images presented by stimulating the occipital lobe during sleep, not real events.

Our five senses can all have hallucinations. Seeing ghosts may just be a problem with the brain nerves and a disorder in the brain's transmission of visual information, but to the experiencer, it is a real thing.

More common than visual hallucinations are auditory hallucinations. You must have experienced auditory hallucinations. When you're waiting for a very important notification, when your full attention is on your phone, you can experience auditory hallucinations because you desperately need the phone to ring. If the senses have illusions, how can we trust them?

The senses are almost the only tools we have to understand the outside world.

Nothing can transcend the senses. If you deny the senses, you deny everything. This view cannot be refuted at all. This is called thorough idealism, and it is serious idealism. Everything is my senses, not that everything is my heart. There is no way to prove that there is something outside the mind, rather than that there is nothing outside the mind. We cannot prove that anything we hear or touch is true.

Seeing this, some people may have jumped up and said, isn’t this nonsense? I punched the wall and my hand was obviously very painful. Is this also a lie? Yes, it may be false, because touch and pain are sensations. Can you prove that there is anything besides sensations?

This is a complete violation of one's will, which cannot be broken or refuted. Idealism is that you cannot prove that there is anything other than the mind, because all your measures are senses. Although you can fight back, you can only fight back to a certain extent. You cannot deny it, but you can ignore it.

Ignorance is not unreasonable, but is based on the high degree of consistency and stability of the world around us. If the moon we see today is made of stone, tomorrow the moon is made of gold, and the day after tomorrow it becomes cake, then of course we can think that we are living in an illusion, but reality is not like this.

All science has discovered that the world we live in has a fairly stable logic. Precisely because the external world is highly stable and consistent, it is completely meaningless for us to question whether the external world is an illusion. We can describe the world and make predictions based on stability and consistency without the additional condition of illusion, so it is natural to ignore it.

We have no reason to believe that the external world exists reasonably, but we have no other choice, just pretend that it exists. ——Hume

Absolute materialism cannot defeat absolute idealism, but it can be ignored. This is not to avoid the problem, but to ignore it reasonably. This is the famous Occam's razor principle, which scrapes away unnecessary assumptions from the theory, leaving the simplest but no simpler explanation. Do not add entities unless necessary. I know that I cannot prove that there is something outside my heart, but I can assume that there is something outside my heart, and that everything in the outside world exists. The outside world has its complete consistency, which you can see, hear, and predict, but cannot be falsified. So until evidence comes out that we are surrounded by hallucinations, we can believe that we are not in a dream.

The torture of the senses and the power of absolute idealism have been mentioned, and the method of cracking idealism has also been mentioned, but is this complete sensory skepticism? No, there is another level of things.

We can believe that what we see before us is true, but is this really the thing itself, is it a fact? Seeing is not the same as reality. It's like a little red flower. Is the little red flower we see the flower itself? Under current scientific conditions, we can categorically say no. We use our eyes to see, but the range of what our eyes can see is limited. We can only see things within visible light waves (380-780 nanometers). We cannot see infrared and ultraviolet rays beyond visible light waves. Does the little red flower glow? It doesn't. Red is the attribute of light. The range of visible light waves is the range of the strongest solar radiation, and the eyes have the ability to detect the strongest radiation of the sun. The small red flower does not emit light; its color comes from reflection of sunlight. No matter what color the little red flower itself is, it must not be red. Red is excluded. What we see is not the color of the little red flower itself, what we see is the light.

This is not only true for the eyes, but also for other organs. The ears can only hear air vibrations between 160,000 and 20,000 HZ; the tongue can only distinguish the four basic tastes of sour, sweet, bitter and salty. Spicy is not a basic taste, it is a pain in the taste buds. Our feelings are limited, and our understanding of ontology is also limited.

We think we are touching the table, but this is not the case. It is just the tactile sensation obtained by the repulsion of electrons reacting to the nerves. The body of the table can never be touched. There is a membrane between us and the body.

We can only use our limited senses to understand a little bit of the phenomenal world, and we cannot touch the ontology of this world.

——Kant

The ontology of the little red flower is an atom, but we cannot see it. There is no color, but we see color. The ontology is atoms, but we cannot see atoms. This is a huge gap. There is an unbridgeable gap between our feelings and the world around us. The little red flower is just a mental image constructed by our brain based on perception. It is abstract and a concept in the mind. We can only think that what we see are small red flowers. This is the limitation of natural talent. Our natural gifts, our sensory deficiencies prevent us from accessing the reality of things, and the forms we see are not real.

So what does this real world look like? Sorry, we don't know enough about this. But don't be sad, we have a way to crack it, or Occam's razor principle. The mental image generated by our perception of the outside world is like a map. The criterion for measuring a map is whether it can take us to our destination. If you can predict, explain, and arrive at your destination based on this map, then it doesn't matter whether the map is the real world. We can still ignore the true appearance of the world and survive based on mental images.

This is enough in terms of evolution. Evolution does not allow us to see the real world, but allows us to survive. It is only through our powerful doubt function that we realize that evolution has not given us the ability to understand the world. But through skepticism, we begin to use science to get closer to the real world.

The real world does exist, but we haven’t cracked its secrets yet.

In the next section, we will talk about another general direction of skepticism.