Division of Ideas

We choose how we organize ideas in our heads.  Take the concept of a wrench.  For me, there are two kinds of wrenches: regular wrenches and monkey wrenches.  That distinction exists because one kind of wrench is useful for binding while the other is good for bashing.  For a mechanic, however, I'm sure there are many kinds of wrenches.

I'm not sure either of us is wrong.  Now, I want to be clear: I am not saying that everyone who believes anything is correct because it's what they believe.  I am saying that someone who looks at a room full of people and sees two groups is every bit as right as someone standing right next to him who sees three groups in that there is no "right" way to divide things into groups, only "useful" ways to do so.

This may be obvious to others but it wasn't obvious to me.  I'm documenting it here as much to ensure I'll have the discovery available for myself when I forget it later as to share it with you.