Others, well understanding the advantages of systematic classification, have proposed to fit their materials, as fast as collected, into their appropriate places in a prearranged scheme. For this purpose they use notebooks of which every page has first been provided with a heading. Thus all the entries of the same kind are close to one another. This system leaves something to be desired; for addi

The use of a commonplace method for historical research is marked as a poor choice because:<br /> The topics with similar headings may be close together, but ideas may not ultimately fit into their pre-allotted spaces.<br /> The classification system may be too rigid as ideas change and get modified over time.

They mention that librarians used to catalog books in this method, but that they realized that their system would be out of date almost immediately. (I've got some notes on this particular idea to which this could be directly linked as evidence.)