Kingsley received letters from Thomas Huxley in 1860, and sent letters in 1863 discussing Huxley's early ideas on agnosticism.

Sanders, Charles Richard (1977). Carlyle's Friendships and Other Studies. Durham, N.C.: Duke University Press. ISBN 978-0822303893.William Griggs, A Guide to All Saints Church, Clovelly, first published 1980, Revised Version 2010, p. 7. Cornish Characters and Strange Events. London: John Lane, 1909 (reissued in 1925 in 2 vols., First series and Second series) Fielding, K. J. (1991). "Carlyle Writes Local History: "Dumfries-Shire Three Hundred Years Ago" ". Carlyle Annual (12): 3–7. ISSN 1050-3099. JSTOR 44945533. Baker, William (1 January 1976). "Herbert Spencer's unpublished reminiscences of Thomas Carlyle: The "Perfect owl of minerva for knowledge" on a "Poet without music" ". Neophilologus. 60 (1): 145–152. doi: 10.1007/BF01513592. ISSN 1572-8668. S2CID 161087774. Tyndall, John (1890). "Personal Recollections of Thomas Carlyle". New Fragments. New York: Appleton (published 1892). pp.347–391.

Emerson, Ralph Waldo (1881). " XVIII. Carlyle". The Complete Works of Ralph Waldo Emerson. Vol. X. Boston and New York: Houghton, Mifflin and Company (published 1904). Plotz, John (2000). "Crowd Power: Chartism, Carlyle, and the Victorian Public Sphere". Representations. 70 (70): 87–114. doi: 10.2307/2902894. JSTOR 2902894.Moore, Carlisle (1957). "Thomas Carlyle". In Houtchens, Carolyn Washburn; Houtchens, Lawrence Huston (eds.). The English Romantic Poets & Essayists: A Review of Research and Criticism (Reviseded.). New York: New York University Press (published 1966). Norton, Charles Eliot, ed. (1883). The Correspondence of Thomas Carlyle and Ralph Waldo Emerson. Boston: James R. Osgood and Company. It is an idle question to ask whether his books will be read a century hence: if they were all burnt as the grandest of Suttees on his funeral pile, it would be only like cutting down an oak after its acorns have sown a forest. For there is hardly a superior or active mind of this generation that has not been modified by Carlyle's writings; there has hardly been an English book written for the last ten or twelve years that would not have been different if Carlyle had not lived. [167] Kingsley has been accused of intensely antagonistic views of the Irish, [13] whom he described in derogatory terms. [19] [20]