Charles Sanders Peirce, Nathan Houser, Christian J.W. J. W. Kloesel (1992). “The Essential Peirce, Volume 1: Selected Philosophical Writings? (1867–1893)”, p.113, Indiana University Press
Letter to Harriot Hunt (1853), as quoted in "The Grimké Sisters from South Carolina: Pioneers for Woman's [sic] Rights and Abolition" by Gerda Lerner, Editorial Oxford University Press, (p. 241), 1998.