Or, to express the same thing differently:
Bringing subjects together so as to form a class.
A catalogue so made is called a classed catalogue.
3. Bringing classes together so as to form a system.
A catalogue so made should be called a systematic catalogue.
The three steps are then
- 1. Classifying the books to make subject-lists.
- 2. Classifying the subject-lists to make classes.
- 3. Classifying the classes to make a systematic catalogue.
The dictionary stops in its entries at the first stage, in its cross-references at the second.
The alphabetico-classed catalogue stops at the second stage.
The systematic alone advances to the third.