by alecto » February 23rd, 2006, 7:24 pm
This is all fascinating! I wish I could get students to think about all these things when I try to teach mathematics. I also wish I could get teachers to think this way when they teach me mathematics.
In any case, some comments:
First, back to adding up the four kids or the two apples. The issue here is an issue of names. Do you remember the term "polynomial"? It means "many names". When we say "you can add like terms" what we mean is "you can add things with the same name". Whenever we reduce something like two apples to either the phrase "two apples" or some mathematical expression like "2a" we're reducing the complexity of the situation by binning together the things with the same names. Whether we can do this depends only on what we mean by the names. Suppose we have ten fruit: two gala apples, three macintosh apples, and five oranges. If I insist on keeping "macintosh" and "gala", I can't add the apples, but if I decide to use the large category, I can say "five apples". I can then choose fruit as an even larger category and say "ten fruit". So it depends on the categories. Let's say the four kids are two girls and two boys. Once I make that split, I can't add them anymore. If I now say they are Lucy, Edmond, Susan, and Peter, I can't add them at all, because now they are uniquely named.
What 2 apples + 2 apples = 4 apples means is that two items that belong to the category "apple" added to two more items belonging to this category yields four items belonging to the category. The fact that adding or multiplying anything we talk about gets us into this category business is one of the things that separate mathematics from hard reality. Reality consists of fantastically complicated objects that we have to simplify tremendously if we are going to do arithmetic concerning them. One of the reasons the Greeks loved geometry was that they could do proofs like they could with arithmetic yet there was still some of the intrinsic nature of the objects left in. It wasn't just words anymore, it was the real shapes of buildings, objects, etc, at least to some extent.
The language question for math, by the way, is the same one there is for translation that complicates the whole issue of what certain things in the Bible mean. The assignment of objects to categories is not trivial. A simple example is that there are no words in English for the kinds of insects that are listed in the OT as being edible, so the translators of KJV picked four approximate categories, some of which in modern usage include no objects even close to those intended in Hebrew.
And it's not just bugs that defy "metacategorization". "Sin" and "faith" do not pick out the same things in English, exactly, as do their Hebrew or Greek counterparts, meaning that some things we call "sins" or "acts/signs of faith" would not be picked out by Hebrew or Greek speakers as examples of the categories picked out by the Hebrew or Greek terms. Ancient Christians were not so affected by these things as moderns are, because they lived in an openly multilingual culture and knew they were dealing with all these different categories. When someone like Augustine tried to discuss things, he often sounded like a philosopher, because he was always trying to get to the bottom of what things meant. Despite the fact that many of us might not agree with what he came up with, I think he was doing a very good job trying to make sense of what he knew was not a trivial problem.
Now I just ran onto how to figure out things like "faith". Rather than trying to define the word somehow, go read all of the examples of the acts of faith and figure out what the commonality is for yourself, without trying to translate into any language. I don't believe all of the things in the Bible are necessarily true, so I might expect some things to just not "fit in", but my list of acts/attitudes will be less like "x acts of faith" and more like a personalized set of examples. Going back to the example of the four kids, it'll be less like "four kids" and more like "Lucy, Edmond, Susan, and Peter".
Sentio ergo est.