Following the controversy in New Hampshire, Abbot left the ministry in 1868 to write, edit, and teach. Abbot's theological position was stated in "Scientific Theism" (1885) and "The Way Out of Agnosticism" (1890). On the latter book Josiah Royce wrote an article so scathing that Abbot took it as an unfair attempt to destroy his reputation, and eventually responded publicly with "Mr. Royce's Libel" (1891 October) in which he sought redress from Royce's employer Harvard University. The debate moved to the pages of "The Nation", where Charles Sanders Peirce took Abbot's side; William James and Joseph Bangs Warner, less so. In his 1903 obituary of Abbot, Peirce praised Abbot's philosophical work and love of truth, and wrote that, in the introduction to "Scientific Theism" (wherein Abbot criticized nominalism and traced it through Kant among others), Abbot "put his finger unerringly [...] upon the one great blunder of all modern philosophy." (For the full texts of the public controversy and the obituary, see "External links" below.)