The 22 categories of words used in Carl Darling Buck's "A Dictionary of Selected Synonyms in the Principal Indo-European Languages" (1949) are quite different from for instance the categories in Roget's thesaurus as of 1911. There is no background in the book itself on how the 22 categories where chosen. Did Buck make the list himself or was he following some (undocumented?) tradition?
Buck's categories are used in at least two other projects, IDS and WOLD, which attribute the categories to Buck. It is a little odd that the history of this categorization-scheme seems to be missing.