Peter Mark Roget - reference source -1905 - p. 77    

The namesake and creator of Roget’s Thesaurus is Peter Mark Roget, a medical doctor and theologian as well as a lexicographer. The thesaurus adopts a tree structure, dividing the English language into six main divisions with numerous subsections connection words by linguistic relation. Aspects of Roget’s schema are derived from the philosophies of Leibniz and Aristotle.

Key elements: Europe