In any Scheme for Classification the sequence of the Main Subjects is not however very important. In the first place each Main Subject will have thousands of books on it forming a single block. Whatever be the sequence of the Main Subjects in the Scheme, these blocks will usually be arranged in a different sequence, in order to satisfy Law 4 of Library Science-Save the Time of the Reader. For example, in a Generalist Library, Literature is the most popular. Therefore, it saves the time of the majority of readers if this block of books is inserted first. Linguistics has only very low priority in the attraction of readers. On the other hand, a subject like History or Economics or Philosophy will attract more readers. Therefore, to satisfy Law 4 of Library Science, these blocks may have to be inserted between the Literature block and the Linguistics block. In other words, a library will have to adopt only a "Broken Sequence" of the Main Subjects. But this need not be done in the catalogue. Secondly, the number of possible sequences of Main Subjects runs to millions. It is impossible to pick one of them as the most helpful sequence. What is wanted is only a reasonably helpful sequence. This book provides a systemic approach to understand this subject. The book will be very helpful for the researchers, veterinarians, students and persons involved in this subject.