"Social Statics, or The Conditions essential to Happiness specified, and the First of them Developed" by Herbert Spencer, (Pt. II, Ch. 4 : Derivation of a First Principle, § 3), 1851.
Judith N. Shklar, Bernard Yack (1996). “Liberalism Without Illusions: Essays on Liberal Theory and the Political Vision of Judith N. Shklar”, p.80, University of Chicago Press
Charlotte Perkins Gilman (2015). “Collected Works of Charlotte Perkins Gilman: Short Stories, Novels, Poems and Essays: The Yellow Wallpaper, What Diantha Did, Women and Economics, The Crux, Moving the Mountain, Herland and other works from the prominent American feminist, sociologist and novelist”, p.454, e-artnow