There are so many anomalies and oddities in Dewey that it would be impossible to cover them all in a basic textbook like this. In this chapter I just want to point out some of the special problems associated with certain subjects, and I will take them in numerical order as they occur.

100 Philosophy

This section is mainly straightforward in use, and contains some of the simplest numbers in the whole of the scheme. There are three main peculiarities to note:

Most people would probably not regard either of these last two as being correctly placed, but their position here is historic and is unlikely to be changed.

200 Religion

This class has been shaped by the fact that for most of its life it primarily meant Christianity, with other religions being relegated to 290–299. This is understandable, as most libraries using Dewey, especially in the early days, have been likely to have more works on Christianity than on other religions. In recent editions some attempt has been made to redress the balance, but the bulk of the class still refers to Christian topics.

You need to be careful in looking at the new numbers 201–209. In the first place, these are not the standard subdivisions of 200, as they used to be; they have all been reused with new meanings. Secondly, you need to remember that the numbers here refer to religions in general; for most of these topics in specific religions there will be other numbers further on.

Within the Christian church, denominations are important, and you will find that in many places you need to specify the denomination before going further.