 Alright guys, hold on, this week we're going all the way down the rabbit hole. Last week I did a video about how I think redness is something that doesn't exist in the world, it's a way of describing the phenomena that we experience. Redness is in the contents of my perception, it's not something that's out there in the world. How far does this line of reasoning go? Let's take something that seems utterly fundamental to the physical world. Let's say we're talking about space. What is space? We have all kinds of experience of space, this stuff. What is it? There is one way of thinking which says that space is another way of representing sense data to your consciousness. In other words, space is also something that only exists in your mind, just like redness. Now I don't actually have this belief per se, or I have it with some qualifications, but here we go. Simple question, do you have any experience of some phenomena outside of your mind? Have you ever experienced anything without your consciousness being an essential part of it? In other words, have you experienced something outside your experience? If you think about that, I think the answer is resounding no. You don't actually have any experience directly of some kind of world outside of your mind. All of your experiences are kind of by default within your mind. A lot of people take this and they run with it and they go, oh my gosh, therefore there's no such thing as a world outside of my mind. But specifically think about space. Do you have any experience of three-dimensional space that exists separate of your conception? I don't think so. 100% of the space that you have experience of is space in your mind, just like 100% of the experience of red that you have is the experience of red in your mind. It may very well be the case that the mind which is taking in all kinds of sense data about what we assume to be the existence of the external world is really painting a picture for your consciousness that may not correlate at all to the way that the world actually is. So I have the positive belief that this is the case with color. I don't think that my representation of red has anything to do with redness in the world, anything that makes sense. I don't think there's such a thing as redness in the world. But that gets a little fishy when we talk about space. Here's the reason why. In front of me I have a pen. When I am talking about the pen, if I'm being really precise, I'm actually just talking about perception in my visual field, blueness and so on. Blueness and whiteness. When I close my eyes, that blueness and whiteness disappears. Disappears comes back. Disappears comes back. So I don't think it's the case that blueness is something fundamental in the world. But here's this crazy thing about space. Even if I close my eyes, I still have other sensations that can be understood within the context of space. I have touch. I'm not having any sensory experience of the pen. And now I feel like I'm moving my arm out in this three-dimensional space. Now I'm feeling the pen, now I'm not feeling the pen, and so on. So even when I close my eyes, it seems like I'm seeing space. But even when I close my eyes, I have this other kind of experience of space. This is also true when you think about your sense of smell. When you smell things, they get stronger and they get weaker. And it appears to be the case that this strongness and weakness of smell correlates with being closer to the smell or farther away from the smell. So it seems like this concept of space, this mental representation of space unifies all kinds of different sensory experiences. It works with sight, it works with sound, it works with taste, it works with smell, it works with feeling. If you feel flames the closer, it seems like the closer you get in this three-dimensional space, the hotter the flames feel. Now to me, that makes me think, well, it's this common thread through all kinds of different sensory experiences. Maybe that implies it's something that is fundamental in the external world or what I assume to be the cause of the contents of my perception. But there's another possible option here. It might not be that space exists in the world. It might be the case that the mind is so constituted as to have found a brilliant way of representing sense data to my consciousness. It might be that space is this concept that our minds have come up with, not due to our own thinking of it, just due to the structure of our own minds, in which it can place all kinds of other sense data. It's kind of the context in which a bunch of other sense data makes sense. Our representation of the world seems to work really well. We seem to be able to navigate around and achieve goals that we want to achieve fairly successfully. So this idea, if you follow this line of reasoning, is where people come up with the concept of idealism. The idea that everything is just an idea. There's no such thing as a mind-independent world. There's no such thing as anything else other than ideas or mental phenomena. Now, that might be true. However, I think it's also compatible with the idea of dualism. We have our representation of the world. We have mental phenomena. I mean, I think we could be certain that mental phenomena were taking place. And we guess, we don't know, we guess that the reason that we're having the sensory experiences we're having is because of the existence of an external world which is impressing upon our senses. The only option here that I think we can probably rule out is physicalism. The idea that everything is mind-independent or that there's no such thing as mind. I think that is certainly false. You got to stick my mental phenomena in somewhere and either they're fundamental or they have this mutual relationship with the existence of the external world. Last thing I'm going to say about this is answering a question that I get somewhat regularly from idealists. They say, Steve, why bother positing the existence of the physical world? Why not just say everything's an idea? That's the only thing we have experience of is the mental world. Therefore, that's all that exists. Here's my response. I have a difficult time understanding why it would be the case that the contents of my perception would be so varied. When I go for a walk down the street, there is all kinds of stuff that's assaulting my senses. There's all kinds of different colors. There's what appear to be little life forms that are moving around that are organized in these crazy ways. Here's an example that I won't get when I'm walking down the street, but you can if you're on Google, is just Googling deep-sea creatures. These crazy things that you couldn't even conceive of. Unless you have a really amazing imagination, which I don't. I couldn't come up with deep-sea creatures if I put my mind to it. They're too ludicrous and complex and crazy. I find it a more compelling theory to say, the reason the contents of my experience are so varied isn't because my mind is just making it up randomly or because all that exists is only minds. No, I find the theory of the existence of the external world, the external physical world, very compelling. If I didn't have as much varied experience that I have, I'd probably be an idealist. But the more time I spend in the world, the more experiences I gain, I go, I didn't come up with this. This is not mental. This is totally crazy. This really almost only makes sense to me right now in terms of the existence of some other world. But I got an open mind. Maybe it's the case that eventually I'll wind up in idealism. If you're an idealist, put your best argument in the comment section. We'll talk about it. Not going to be a physicalist. I think that's certainly false. I'm stuck in dualism right now, but who knows? Maybe someday I'll make that leap to only ideas exist. We'll see.