Roget's Thesaurus of English words and phrases.

it encourages the exploration of shades of meaning ,of comparing directly the one word with another that is almost synonimous 'On addition ,each category is printed beside the subcategory that most nearly reflects its antithesis.There is an index at the back of the book,which is arranged by individual words.Within the entry ,each word is further boken down into its various meanings,with references to the subcategory in the text proper.The index is so specific that a word may have as many as twenty different references.Rude for example,is broken down into ten possible contexts,reflecting the variety of meanings it may assume_"violent","shapeless","Inelegant","uncivil",The keyword for each subcategory is printed in bold-faced type.It is followed by a list of synonymous nouns,then verbs,adjectives,adverbs,etc.Under each part of speech ,the most closely related synonyms are grouped together in paragraphs.Finally there is a list of phrases and idiomatic expressions ,for often a phrase is the only way to get at the true thought .Slang expressions that have become the part of the language are also given.Foreign words that have been naturalized are included,as foreign words that have no literal translation in English and serve a distinctive role in the English language.

Organized by general categories Namely:1)abstract relations 2) space 3)matter 4)intellect 5)volition 6)affection that reflect the most common patterns of the word's and their usage in the English language .An introductory synopsis of the genral categories describes in detail the subcategories within each general category .The format of the thesaurus embodies the principle that form must follow function.And the function of the thesaurus is to facilitate the precise expression of ideas