^Locke, John. A Letter Concerning Toleration Routledge, New York, 1991. p. 5 (Introduction)
^Delaney, Tim. The march of unreason: science, democracy, and the new fundamentalism Oxford University Press, New York, 2005. p. 18
^Godwin, Kenneth et al. School choice tradeoffs: liberty, equity, and diversity University of Texas Press, Austin, 2002. p. 12
^Becker, Carl Lotus. The Declaration of Independence: A Study in the History of Political Ideas Harcourt, Brace, 1922. p. 27
^Baird, Forrest E.; Walter Kaufmann (2008). From Plato to Derrida. Upper Saddle River, New Jersey: Pearson Prentice Hall. pp. 527–529. ISBN0-13-158591-6.