do group synonyms together. Gabriel Girard, La Justesse de la langue françoise, ou les différentes significations des mots qui passent pour synonymes (1718) John Trusler, The Difference between Words esteemed Synonyms, in the English Language; and the proper choice of them determined (1766) Hester Lynch Piozzi, British Synonymy (1794) James Leslie, Dictionary of the Synonymous Words and Technical Terms in the English Language (1806) George Crabb, English Synonyms Explained (1818) Roget's Thesaurus, first compiled in 1805 by Peter Mark Roget, and published in 1852, follows John Wilkins' semantic arrangement of 1668. Unlike earlier synonym dictionaries, it does not include definitions or aim to help the user to choose among synonyms. It has been continuously in print since 1852, and remains widely used across the English-speaking world. Roget described his thesaurus in the foreword to the first edition: It is now nearly fifty years since I first projected a system of verbal classification similar to that on which the present work is founded. Conceiving that such a compilation might help to supply my own deficiencies, I had, in the year 1805, completed a classed catalogue of words on a small scale, but on the same principle, and nearly in the same form, as the Thesaurus now published. Organization Conceptual Roget's original thesaurus was organized into 1000 conceptual Heads (e.g., 806 Debt) organized into a four-level taxonomy. For example, debt is classed under V..iv: Class five, Volition: the exercise of the will Division Two: Social volition Section 4: Possessive Relations Subsection 4: Monetary relations. Each head includes direct synonyms: Debt, obligation, liability, ...; related concepts: interest, usance, usury; related persons: debtor, debitor, ... defaulter (808); verbs: to be in debt, to owe, ... see Borrow (788); phrases: to run up a bill or score, ...; and adjectives: in debt, indebted, owing, .... Numbers in parentheses are cross-references to other Heads. The book starts with a Tabular Synopsis of Categories laying out the hierarchy, then the main body of the thesaurus listed by Head, and then an alphabetical index listing the different Heads under which a word may be found: Liable, subject to, 177; debt, 806; duty, 926. Some recent versions have kept the same organization, though often with more detail under each Head. Others have made modest changes such as eliminating the four-level taxonomy and adding new heads: one has 1075 Heads in fifteen Classes. Some non-English thesauri have also adopted this