The Problem of Skepticism about the External World and The Analysis of Perception are two of the twelve problems in the philosophy of mind according to John Searle, Mind: A Brief Introduction. I have chosen to speak about both problems in conjunction because I feel I cannot speak about one without referencing the other.
Sometimes I lay awake at night wondering. Many questions float across my mind. One of the questions that keeps me awake 'is this real?'. These three words alone spawn many questions. The first question is what do I mean by 'this'. Here the best answer that I can give myself is - my perception of reality. I wake up every day, I eat food, I interact with people, I feel things and I think things. How do I know if it is what actually exists?
But then again, to answer the question of 'is this real' I first need to understand what 'real' means. The dictionary definition of real is: actually existing as a thing or occurring in fact; not imagined or supposed. Thus we cannot talk about reality without discussing what 'imagination' is. Once again revisiting the dictionary, it defines imagination as the faculty or action of forming new ideas, or images or concepts of external objects not present to the senses. Again this springs up a new question. What are the senses? This I think is something I can answer without checking the dictionary. We know we have five senses- sight, touch, smell, taste and sound. These are the five different types of inputs I can get from the external world. And then I react and give some output. Sometimes these outputs may be visible to me, like I may run if I see a dog chasing me. Sometimes I am listening to music, or watching a movie and this causes my body to react in ways I cannot wilfully, like my heart rate increases.
So basically, I am like a machine. I take inputs and give outputs. My mind would be the CPU that does the processing. So whatever I am perceiving is a picture made by computations made in my mind. But what if we had ten senses? That means we have five more different ways of getting different information about the outside world. Clearly, what we percieve as reality would be different. I imagine it would be similar to the difference between a two dimensional and three-dimensional image. It's like a machine learning model. If you give it fewer parameters to work with it will form some model of the problem. This model may not be correct. But it's the best the machine can do. That's what 'reality' is for the machine. So what if what I am perceiving as the external world is my mind's mediocre perception of what true reality is? We exist in 3-D reality. Our mind cannot perceive what the fourth or fifth dimension would be, but what if it exists?
I would also like to discuss the effect of drugs on the mind. People are said to see 'illusions' when they are high on drugs. When someone is hallucinating they are labelled as 'crazy' or 'out of their minds'. Why do we call them crazy? Just because what they perceive as reality is different from what the rest of us do. Drugs are just catalysts that participate in the equation of inputs to outputs. How do we know that we are not the crazy ones and drugs are not just a glimpse into what is 'true' reality?
Another thing I wonder is: in what form do other people perceive reality. And how do I know that what they are perceiving as reality is the same as my perception? Suppose there was a superior mind that could switch through seeing the world through different eyes like changing a pair of glasses. Would all these versions look the same? For example, what if all our eyes perceive color differently? Like the dna's interpretation of the color of an apple is different in everyone? I think green means some color but it could look like my yellow to someone else. So someone sees yellow trees everywhere! This is fascinating. I don't think there's any way for us to ever know if what each of us percieve using our senses is the same or different, because if any physical proof exists, our perception of that proof would also be interpreted using the same five senses!!
But all of this is assuming the external world is real. I spoke earlier about how we are similar to a machine. We take input and give output. But we humans also create other machines and give them inputs. How do I know that someone is not feeding me inputs? There are five inputs needed to be supplied to me. What if my mind is floating in a lab and there are wires connected to it, and I am being given inputs which make my mind percieve reality. My only affirmation of if something 'exists' is if I can see, hear, feel, smell or taste it. We know coronavirus exists because we see its effects and we can extract and observe its DNA. That is why we determined that it exists. It could very well be that everyone is lying to me, I could be in a situation similar to the 'Truman Show'. How can I possibly know if I am or not?
I think that answering all these questions is impossible through any physical proof. Reality is what I perceive, and there is no way of knowing if what I am perceiving is correct, or even existent. However, I do think that whether or not it is real is immaterial. If I believe I am in a simulation it will not change the way I am perceiving reality, the brain according to its DNA and composition will continue to produce similar outputs. So although this might be an anti-climatic conclusion, maybe it doesn't really matter if what I am perceiving is reality or not. The fact of the matter is that it is now my concept of reality, so I had better deal with it.