His earliest poem is the Livre des quatre dames, written after the battle of Agincourt.
The form in which certain of the references to him are couched favours the above view; the compiler of Guiron le Cortois says in his prologue that "maistre Gautier Map qui fu clers au roi Henrydevisa cil l'estoire de monseigneur Lancelot du Lac, que d'autre chose ne parla it mie gramment en son livre"; and in another place he refers to Map, "qui fit lou pro pre livre de monsoingnour Lancelot dou Lac."
He was responsible, especially, for the great operation known as the opening of the Grand Livre (August 2 4), which was designed to consolidate the public debt by cancelling the stock issued under various conditions prior to the Revolution, and issuing new stock of a uniform character, so that all fund-holders should hold stock of the revolutionary government and thus be interested in its stability.
In addition to other medical works he published anonymously Conjectures sur les memoires originaux dont it parait que Moyse s'est servi pour composer le livre de la Genese, (1753), in which he pointed out that two main sources can be traced in the book of Genesis; and two dissertations on the immateriality and immortality of the soul,.
The book begins with a short avis (address to the reader), opening with the well-known words, "C'est icy un livre de bon foy, lecteur," and sketching in a few lively sentences the character of meditative egotism which is kept up throughout.
