Williams now supported himself by taking private pupils. After the speech of Sir George Savile on 17 March 1779 in favour of an amendment of the Toleration Act, Williams published a letter on "The Nature and Extent of Intellectual Liberty", 1779, claiming that religious toleration should be without restriction. It was answered by Manasseh Dawes. In the same year, and with the same object, he translated and published Voltaire's "Treatise on Toleration", "Ignorant Philosopher" and "Commentary on Beccaria". In 1780 he issued "A Plan of Association on Constitutional Principles"; and on the formation of county associations for parliamentary reform he published his "Letters on Political Liberty" (1782). This was translated into French the following year by Jacques Pierre Brissot, then in London conducting the Lyceum. Jean-Marie Roland, vicomte de la Platière, a friend of Brissot, visited London in 1784, when Williams made his acquaintance.