Everything we know, everything we perceive, comes to us through the filter of our senses, and is then interpreted into a part of our map, our inside world. There is only one exception to this fact, one more direct contact with the mystery which is the real world, and we will get to that a little later.
"Sameness implies difference, and, by the same token, difference implies sameness."
Aside from that one exception, when I say everything, I mean everything. The "outside" world does not stop, for instance, at your skin. Do you feel a pain in your left arm? That pain comes to you through your nerve endings—one of your sense organs—in that arm, and the way you know it is in your arm is by interpreting it in relation to other senses (sight, for example) and fitting it into your inside world, which includes your "map" of your own body.
Even what we know about ourselves is a result of this mapping process by which we create the world of our experience. Emotions? Think of what it feels like to be "sad". That welling up behind the eyes, the sagging feeling in the back of the throat or shoulders, or, if that's not how you do it, think of the feelings you do get. Those are sense impressions, which you have learned to interpret as "sadness".
And how do we do this? How do we interpret all these sense impressions into an imagined world, which is an accurate enough map of the world outside? We do it by drawing analogies.
When I see the duck-rabbit sketch as a duck, I am drawing an analogy between a squiggly line and dot on a computer screen and all the ducks I have ever seen before. When I look at my desk, and see my mug, I am drawing an analogy between the set of sense impressions that mug gives me, and the sense impressions I have received from other mugs.
These analogies can be very complex, and very sophisticated, because you and I are very good at drawing them.
I have a book by the Monty Python crew, which has, on the back cover, two pictures side by side. The first is a picture of the Pythons dressed as Gumbys with handkerchiefs on their heads, stupidly facing the camera in a row. The second is an aerial shot of a large city. The caption reads "There are exactly 8,351,279,446,365 differences in these two pictures. Can you spot them all?"
Why do I laugh whenever I see that? It's because of a whole cascade of analogies.
I see it as like (a positive analogy) all of those little exercises in children's books, where we are asked to find the differences between two pictures which are almost, but not quite identical. Maybe someone is wearing a cap in one picture, but a cowboy hat in the other. A child rides a tricycle in one picture, and bicycle in the other.
And the joke, of course, comes from the difference (a negative analogy) between those pictures and these two. These two pictures are not enough alike for us to spot any differences. They aren't completely different, of course. They are both pictures. If they weren't, we might not get the joke.
It turns out that this interplay between sameness and difference, between positive and negative analogy, is fundamental to all categories, all perception, all knowledge. It makes no sense to talk of difference in the absence of sameness, and no sense to talk of sameness if there is no difference.
It might appear otherwise at first glance. You might think, for example, that it makes perfect sense to say that two coins are completely identical, but it does not. In order to be alike they must be different—if only because one is on the right, and the other is on the left. Otherwise they would not be two coins, but one. And it would be pointless to talk about the similarity of a coin to itself.
It's like the story of two men arguing whether Lake Lemans or Lake Geneva is more beautiful. A third man points out that the two are synonymous. Whereupon one of the first two replies "Yes, of course, but Lake Lemans is by far the more synonymous of the two.
Sameness implies difference, and, by the same token, difference implies sameness. The Monty Python photos are not similar enough, so it makes no sense to speak of differences.
It's from this fabric of sameness and difference that we weave our inside world. From the sameness and difference of the pictures our two eyes provide we create a three dimensional picture. From the similarities and differences in timing, loudness, location, etc. between what we hear and what we see we place sounds in those three dimensions.
From similarities and differences of various experiences, we create categories which define our expectations. We expect different behavior from a shadow on the wall, for example, then we do from a solid object like my mug.
Similarity and difference tell us that your mug and mine are both mugs, but not the same mug. They allow us to diagnose disease, choose what we want for dinner, spot a friend across a crowded room. They are the way we navigate the sea of mystery that we live within, and the tool we use to create the map that is our inside world.
Even numbers are fundamentally analogical. Bertrand Russel has said that "Mathematics began when it was discovered that a brace of quail and a couple of days had something in common: the number two."
There's a lot more to this process of building a world through analogy, and more, as well,about its relationship to mystery, but first, I said that there was one exception—one bit of contact with mystery which stood outside analogies drawn between sense impressions.
We'll take a quick look at that exception in part 8.
