Ideals and Ideas
I had a fascinating discussion with an old friend of mine about my contention that everything has momentum. He wondered how an idea could have mass. Ideas seem to exist without any material substance.
This is a subtle point. What our intuition tells us about ideas being without mass is compelling. It’s the same line of reasoning as the Platonic ideal.
Plato (Socrates actually) noticed that all trees look like trees, but no two are actually the same. A particular oak is different from a pine or even from another oak, and yet we have no trouble knowing that despite their differences they are all trees. He decided that there is a level of existence in which the ideal tree exists, and all trees approximate that ideal tree.
When you talk about an idea, you assume that I will agree with you on exactly what that idea is, but how could I? We have different approaches and no matter what the idea is, the more we drill down into it, the more we will find slight differences between our understandings. Yet does the idea, in its pure form, exist somehow? Maybe. We can’t know for sure, but it doesn’t have to in order to understand our experience of ideas.
Let's jump to songs. A song exists from singer to singer. It is an idea. It exists in people’s minds until a singer sings it. But any sung version is just a version of the song, it's not the song. When you sing “Happy Birthday”, it isn’t exactly the same as when I sing it. In fact, it isn’t the same from one time you sing it to the next time you sing it. Every performance is different because of the immediate circumstances: the room, the person sung to, the others singing, the sound of your voice on that particular day, etc. There is no ideal, no one example that we can point to as the real song. There are only instances of the song; instances of the idea. Still, we know they are all the same song, “Happy Birthday”, because of enough similarities in lyrics and melody.
The reason we know what a tree is, is because we have agreed, from lots and lots of examples of trees, that there is a general form for which anything that falls within certain boundaries, we class as a tree. This isn’t the same as a single ideal tree.
This agreement we have doesn’t exist except in our individual minds, in patterns of physical neurons firing. Each of us will have slightly different opinions on the boundaries of that agreement. Plato understood this. If all humans were suddenly erased from the universe (not impossible by a long shot, in his time or in ours) the idea of a tree would be erased also, unless there is another level of existence in which the idea exists eternally as the ideal. Believing that we couldn't have originated the concept of "tree" without the ideal, he postulated it.
There is no way to prove or disprove the existence of the ideal, but our experience would be no different either way. What we think of as an ideal can be explained completely as our personal (in our physical brains) average of all our experiences of particular examples of that idea. And the idea is personal, not universal. It is universal only insofar as we discover that our versions of the idea overlap.
When I say “tree” you know what I’m talking about even though your mental image of “tree” is certainly not exactly same as mine. That doesn’t matter usually. If I show you the exact tree I’m talking about, you will agree that it is a tree, even though it isn’t the exact tree you imagined. We can all communicate because we mostly agree on what a tree is, but it can never be perfect, a single ideal.
Our ideas exist only as individual patterns of neurons firing in our individual brains. Ideas are material. They have mass, motion, space, and time. They have momentum.