And the Lord God said, It is not good that the man should be alone; I will make him an help meet for him. (Gen 2:18 KJV)
Just as it was not good for Adam to be alone in the world, so it was not good for the OED to be the solitary representative of the English language on Earth. After nearly 45 years of taking the ribs out of the OED and sorting them by kind, a group of dedicated philologists have created the perfect mate for the OED, the Historical Thesaurus of the Oxford English Dictionary (available at Amazon). Naturally it is the largest thesaurus ever produced, and the only historical thesaurus in any language. It contains all of the OED entries up to the second edition additions (they had to stop somewhere!) and is arranged semantically by a structure created specifically for this project.
I’m sure half the pleasure of the HTOED is browsing through the categories of words, but if you are looking for something in particular, there is an alphabetical index volume to go with the thesaurus. Together they form a two-volume boxed set that is about the same size as the Shorter Oxford English Dictionary. I think they would look quite handsome on the shelf together. I think it is a good sign, in these days of e-books and online references, that Oxford has published this monumental thesaurus in book form. I will most definitely be saving up my pennies to get my own copy!
Find out more about the HTOED and see a sample page here.