The other day, I wrote a post about the song “Do You Hear What I Hear?”. My dad pointed out to me yesterday that I missed a great opportunity for some philosophizing. He’s right. The question, “Do you hear what I hear?” is a philosophical puzzle. So are the two other questions in the song, “Do you see what I see?” and “Do you know what I know?”
The first two, about seeing and hearing, are things that many people wonder about from time to time. Does blue look to you like it looks to me? Does a middle C sound the same to me as it does to you? If it’s different, it could help explain differing tastes. Unfortunately, outside of a Freaky Friday type of body switch, I think it’s impossible to know. There’s just no way to describe a color or a sound without reference to things that are that color or make that sound.
I suspect that all humans hear and see the same things when they hear or see something. We all have basically the same apparati for our sensory perception. I imagine other animals, though, perceive sights and sounds much differently that we do. I don’t mean a matter of degree either. I mean a real substantive difference. When a dog sniffs something it doesn’t smell the same thing we do, just more powerfully. We can’t even grasp what is going on when a dog smells. Wittgenstein has a famous quote about how if a lion could talk, we couldn’t understand it. That’s because the lion’s experience of the world, which includes sensory perception, is so radically different than our own.
“Do you know what I know?” seems like a completely different type of question. I don’t mean it in the sense of whether I have more or different information than you. I mean it in the sense that if we both know that 2+2=4, do we know the same thing? A lot of people’s knee jerk reaction is that we do know the same thing, that 2+2=4. But how do I know if 2, +, =, and 4 each mean the same thing to you that they do to me?
For people who believe that facts are out in the world, or those whole believe in Forms, we likely do know the same thing. We know whatever that thing that’s out in the world is. But what if knowledge is in our minds? That would mean that there’s a separate instance of knowledge for each knower. Which could mean that each instance is different, and, like colors and sounds, we would never know. I like the idea that we know different things, that you do not know what I know. I have no idea if it’s true or not, but I like it.
Ultimately, these are trees falling in a forest type of questions. There’s no way to test them to find out. I’m pragmatic about them. As long as we can coherently talk to each other, who cares? They are fun to ponder, though.