 He also constructed his case as a specific response to writings of William Godwin (1756–1836) and of the Marquis de Condorcet (1743–1794).His assertions evoked questions and criticism, and between 1798 and 1826 he published six more versions of "An Essay on the Principle of Population", updating each edition to incorporate new material, to address criticism, and to convey changes in his own perspectives on the subject.Even so, the propositions made in "An Essay" were shocking to the public and largely disregarded during the 19th century.