[not] + [do] + [or] -- order
Let us imagine dividing a poetic line into three segments.
1 | 2 | 3
Semantically, the middle is least important, the end is most important, and the beginning is somewhere between the two. In other words, we experience the following.
2 | 3 | 1
This phenomenon shows that *order* is of fundamental importance in aesthetics.
In Chapter 4 of Introduction to Mathematical Philosophy, Bertrand Russell lists three mathematical characteristics of order. We use < as our operator here, but any symbol will do.
(1) Asymmetry. If x < y, then it is not the case that y < x.
(2) Transitivity. If x < y and y < z, then x < z.
(3) Connected. For all x and y, either x < y or y < x.
At first glance, order appears to be axiomatic and atomic, a thing complete in itself. However, Russell shows that it can be broken down into even more basic components. It reinforces the power of thinking of aesthetics in terms of primitive cognitive structures.