Locke’s Principle of Proportionality

Mark Boespflug 1
  • 1 Philosophy Department, University of Colorado Boulder, 232 UCB Boulder, Boulder, USA
Mark Boespflug
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  • Philosophy Department, University of Colorado Boulder, 232 UCB Boulder, CO 80309, Boulder, USA
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Locke’s principle of proportionality – among his most important contributions to philosophy – states that we ought to apportion our assent to a given proposition in accord with the probability of that proposition on an adequate body of evidence. I argue that treatments of Locke’s principle fail to avoid interpreting it as a fundamentally doxastic prescription – a precept concerning how we ought to voluntarily control our assent. These interpretations are problematic on account of their implications concerning the degree of control that agents have over the doxastic process, and on account of how they cohere with numerous texts in the Essay. I suggest that the principle, instead, commends that we engage in certain activities, or practices, that tend to produce true beliefs.

  • Alston, W. 1989. Epistemic Justification: Essays in the Theory of Knowledge. Ithaca.

  • Audi, R. 2008. “The Ethics of Belief: Doxastic Self-Control and Intellectual Virtue.” Synthese 161, 403–418.

  • Ayers, M. 1991. Locke; Volume I: Epistemology. New York.

  • Bolton, M. 2008. “Intellectual Virtue and Moral Law in Locke’s Ethics.” In Contemporary Perspectives on Early Modern Philosophy; Essays in Honor of Vere Chappell. Eds. P. Hoffman/D. Owen/G. Yaffe. Peterborough, 253–272.

  • Buchak, L. 2014. “Belief, Credence, and Norms.” Philosophical Studies 169, 285–311.

  • Dougherty, T. “The Ethics of Belief is Ethics (Period): Reassigning Responsibilism.” In The Ethics of Belief: Individual and Social. Eds. J. Matheson/R. Vitz. Oxford, 146–167.

  • Goldie, M. (ed.) 1997. Locke: Political Essays. Trans. by P. Abrams. Cambridge.

  • Hubert, F. (ed.) 2009. Degrees of Belief. London.

  • Klibansky, R. (ed.) 1968. John Locke: Epistola de Tolerantia; A Letter on Toleration. Trans. J. Gough. Oxford.

  • Locke, J. 1997. “An Essay on Toleration.” In Goldie 1997.

  • –. 1997. “The First Tract on Government”. In Goldie 1997.

  • –. 1979. An Essay Concerning Human Understanding. Ed. P. H. Nidditch. New York.

  • –. 1968. “A Letter on Toleration.” Trans. Gough. In Klibansky 1968.

  • Lolordo, A. 2016.“Locke on Knowledge and Belief.” In A Companion to Locke. Ed. M. Stuart. Malden, 296–312.

  • Losonsky, M. 1996. “John Locke on Passion, Will and Belief.” British Journal for the History of Philosophy 4, 267–83.

  • –. 2003. Enlightenment and Action From Descartes to Kant: Passionate Thought. Cambridge.

  • Passmore, J. 1986. “Locke and the Ethics of Belief.” In Rationalism, Empiricism, and Idealism. Ed. A. Kenny. New York, 23–46.

  • Plantinga, A. 1993. Warrant: The Current Debate. New York.

  • Ryle, G.2009. “John Locke”. In Critical Essays, collected papers of G. Ryle. New York.

  • Schouls, P. 1992. Reasoned Freedom: John Locke and Enlightenment. Ithaca.

  • Stuart, M. (ed.) 2016. A Companion to Locke. Malden, 2016.

  • Tully, J. 1988. “Governing Conduct.” In Conscience and Casuistry in Early Modern Europe. Ed. E. Leites. Cambridge, 12–71.

  • Wolterstorff, N. 1996. John Locke and the Ethics of Belief. Cambridge.

  • Woolhouse, R. 2007. Locke: A Biography. New York.

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