He received no formal schooling, but by self-study he learned to read and write, and taught himself several ancient and modern languages.
While at Finsbury, Carpenter became acquainted with the philologist William Greenfield, editor of Samuel Bagster the Elder's polyglot Bibles, and began co-editing Scripture Magazine, which they eventually expanded into the four-volume work Critica Biblica in 1824–1827.
[2] This employment allowed him to devote time to literary pursuits, and he began writing theological and general works, establishing himself as contributor to and editor of numerous periodicals.
In 1830 he issued a series of Political Letters with which he attempted to defy the stamp duty on newspapers, but in May 1831 he was tried and convicted of evading the law and was imprisoned.
He became intensely involved in the cause of political reform, publishing numerous tracts and books on the subject through the late 1840s.