For those confused as I was: https://en.wikipedia.org/wiki/Peter_Mark_Roget
“Peter Mark Roget (18 January 1779 – 12 September 1869) was a British physician, natural theologian, lexicographer and founding secretary of The Portico Library. He is best known for publishing, in 1852, the Thesaurus of English Words and Phrases, a classified collection of related words.”
