John Horne Tooke were his friends, and he maintained correspondence with supporters of radicalism. Francis Place acknowledged an intellectual debt to Frend. Frend's Unitarian network, as well as the group round Priestley, included James Gifford the elder and Robert Hibbert. When it came to Godwin, Frend like others had difficulties with his atheism. He was frequently consulted by John Palmer in support of his claim for a public grant for his services in improving the transmission of letters. Frend thought that the rate of postage should be reduced to a fixed charge of one or two pennies, and drew up a statement to that effect. It reached a member of Robert Peel's cabinet, but nothing came of it at that time. Works Frend's works dealt with many subjects. His publications were: An Address to the Inhabitants of Cambridge and its Neighbourhood ... to turn from the false Worship of Three Persons to the Worship of the One True God (St. Ives, 1788). The second edition was entitled An Address to the Members of the Church of England and to Protestant Trinitarians in General, and it was followed by A Second Address to the Members of the Church of England. These were reprinted in Six Tracts in Vindication of the Worship of One God, and in other unitarian publications, and were answered by the Rev. Henry William Coulthurst, by George Townsend of Ramsgate in two tracts (1789), and by Alexander Pirie in a volume issued at Perth (1792). Frend responded in Thoughts on Subscription to religious tests ... in a letter to the Rev. H. W. Coulthurst, and in Mr. Coulthurst's blunders exposed, or a review of his several texts. For these pamphlets Frend was expelled from the Society for Promoting Christian Knowledge (An Account of some late Proceedings of the Society (1789). Peace and Union Recommended to the Associated Bodies of Republicans and Anti-Republicans (1793) Peace and Union recommended, &c., 1793; (2nd ed. 1793), in which he described the evils of the then parliamentary system and of the game and poor laws, and explained the necessity for numerous reforms. The offending passages are set out in the second edition in single inverted commas. Scarcity of Bread: a plan for reducing its high price (1795), two editions. He urged subscriptions by the rich for the relief of the poor. Principles of Algebra (1796) (with a very long appendix by Francis Maseres)