* Schwitzgebel, E.: Do Ethicists Steal More Books? Philosophical Psychology 22, 2009
** Iyer et al.: Understanding Libertarian Morality PLoS ONE 7(8), 2012
*** Royzman et al.: The Curious Tale of Julie and Mark Judgment and Decision Making, Vol. 10, No. 4, 2015
- Hume: An Enquiry Concerning the Principles of Morals, Appendix I: "... morality is determined by sentiment. It defines virtue to be whatever mental action or quality gives to a spectator the pleasing sentiment of approbation; and vice the contrary."
- Kant: Groundwork for the Metaphysics of Morals, 4:389: "Everyone must grant that a law, if it is to hold morally ... as a ground of an obligation, must carry with it absolute necessity ... the ground of obligation here must not be sought in the nature of the human being or in the circumstances of the world in which he is placed, but a priori simply in concepts of pure reason."
- Haidt: The Righteous Mind Vintage 2013
Images of Kant and Hume commissioned for this publication from artist Georgios Magkakis.