I was very surprised to learn that Roget never intended the thesaurus as a book of synonyms. He didn't believe there was such a thing as synonyms, since every word has a distinct meaning. But he was mentally ill, or at least mentally unstable, and one of his compulsive coping mechanisms was making lists.
I was also surprised - amazed, startled, astonished, shocked? - to learn that the thesaurus was not Roget's life work.
The Thesaurus, a retirement venture carried out when Roget was in his 70s, may have been prompted by a reissuing, in 1849, of "British Synonymy," a handbook of definitional equivalents first published a half-century earlier by Hester Lynch Piozzi, known to devotees of Dr. Johnson as his friend Mrs. Thrale. Freshly exasperated by the volume's haphazardness, Roget soon set to work in earnest on his own production.
Never quite intended as a book of synonyms (Roget thought there "really was no such thing," given the unique meaning of every word), the Thesaurus was constructed as a crystal palace of abstraction, each of whose 1,000 lists pushes a reader, often antonymically, to the next, "certainty" leading to "uncertainty" leading to "reasoning" leading to "sophistry." The truth is that most users of the Thesaurus have never made head nor tail of the system and have just availed themselves of the index — added by Roget almost as an afterthought — to find what they are looking for.
The book was a hit with the English public from the moment it appeared in 1852; a bowdlerized American edition — dropping such objectionable exciters as "aria" and "the ups and downs of life" — appeared two years later. Roget continued revisions and updates until his death at 90, and his heirs kept the book going as a kind of family concern for a full century, before the name, like Webster's, passed into the public domain. Since 1852, Roget's has, Kendall explains, "lost 10 concepts — it's down to 990 — but it has gained a couple hundred thousand new words."
I love thesauri, although I rarely use one anymore. I like to keep my writing simple and straightforward; I'm more likely to use a dictionary to clarify a word's meaning. But I love looking at the vast array of somewhat synonymic words. When I open a thesaurus, I get lost, the way I get hypnotized by reading place-names on a map.
My mother bought me a hardcover thesaurus when I was in junior high school. A hardcover book was a big deal in our house, and her gift was an affirmation of me as a writer. The edition itself is now a bit archaic, and not the thesaurus I reach for, but I'll never part with it.