The Moral Judgments Project

A Psychology-Philosophy Collaborative at UC San Diego

About the Project

Moral philosophers are engaged in the challenging project of identifying the true ethical principles that capture how human beings are obligated and permitted to act. Is it permissible to kill one person in order to save five others? Is it permissible to act in a way that harms innocent civilians as a foreseen but unintended byproduct of bombing a munitions factory that will bring an earlier end to a terrible war? The right answers to these questions are needed to know how we should act. Meanwhile, many psychologists are exploring what ethical principles people actually use when making morally charged decisions. While philosophers are engaged in a normative project, psychologists ask empirical questions about our actual practices. But such a neat dichotomy in aims does not perfectly reflect the nature of each inquiry. Philosophers often appeal to facts about ordinary ethical intuitions to support their normative claims, and at least some prominent psychologists go on to draw ethical conclusions from their results. Our project brings these two kinds of inquiries together in a systematic and rigorous way.   We focus on three moral principles: (1) The doctrine of double effect: that it is more difficult to justify intending harm than it is to justify merely foreseeing harm; (2) The doctrine of doing and allowing: that it is more difficult to justify doing harm than it is to justify merely allowing harm; and (3) The doctrine of allowing and enabling: that there is no morally relevant difference between allowing harm and enabling harm. Our aims are to discover whether, and if so, how, moral principles are justified and to gain better understanding of how people reason morally in the ultimate service of improving human conduct.


-Our article, "Intuitive Probabilities and the Limitation of Moral Imagination," has just been published (early view) in Cognitive Science. (Click here for supplementary materials.)

-We are very pleased to have received a UC San Diego Chancellor's Research Excellence Scholarship grant for 2018-1019 for our project, "The Psychological and Philosophical Foundations of Probabilistic Moral Principles", and a grant from the UC San Diego Institute for Practical Ethics for our project, "Probabilistic Moral Judgments in Action: Decisions in Wartime and Driving".

The Team

Nicholas Christenfeld

Nicholas Christenfeld was educated at Harvard and Columbia where he earned, or at least received, a B.A. and a PhD in psychology. He then became, and plans to remain, a professor of psychology at UC San Diego. There he studies an array of topics broadly, if perhaps unhelpfully, described as the social psychology of everyday life. His research has addressed such questions as why a baseball season is ten times as long as a football season, how people choose which box of Cheerios to take from the supermarket shelf, whether babies resemble their parents, and dogs their masters, if story spoilers actually spoil stories, which gender is funnier, when during the month one is likely to die, and whether visiting New York City would make that outcome more likely, who says “um,” whether music does soothe the savage breast, why it might be hard to tickle oneself, if men are more prone jealousy, and why one’s heart would be grateful if one made more friends.

Dana Kay Nelkin

I am a Professor of Philosophy at the University of California, San Diego, and an affiliate professor at the University of San Diego School of Law. I received my B.A. in Philosophy and Plan II (Liberal Arts) at the University of Texas at Austin, and my Ph.D. in philosophy at UCLA. My central areas of research are ethics and moral psychology, and these lead me into related areas such as philosophy of law, philosophy of agency, and social psychology. I have written articles on a variety of topics including forgiveness, friendship, self-deception, and the lottery paradox, as well as a book, Making Sense of Freedom and Responsibility.

Samuel Rickless

I am a Professor of Philosophy at the University of California San Diego, and an affiliate professor at the University of San Diego School of Law. I received a B.A. from Harvard, a B. Phil. from Oxford, and a Ph.D. from UCLA. My research spans a number of philosophical subfields, including normative ethics, philosophy of law, philosophy of language, and the history of Western European philosophy (particularly, Plato, Locke, Berkeley, and Hume). My work in normative ethics focuses on the elaboration and defense of non-consequentialist principles, including the doctrine of doing and allowing, the doctrine of direct-indirect harm, and the doctrine of allowing and enabling. My work in the philosophy of law focuses on the right to privacy, fourth amendment jurisprudence, and legal interpretation.

Arseny Ryazanov

I am a fifth-year PhD student in psychology at the University of California San Diego. My research explores several facets of prosocial behavior. One project examines the balance between thinking of oneself as having infinite potential and being constrained by the actual state of the world, and how this balance relates to treatment of others. Another explores the extent to which performance metrics can encourage charitable donation.



Tinghao Wang

I am a second year Ph.D. student in philosophy at the University of California, San Diego. I’m interested in epistemology (especially questions about evidence and higher-order rationality), ethics (especially questions about moral responsibility and agency), philosophical methodology (especially questions about intuitions), and experimental philosophy.






Jonathan Knutzen

I am a fifth year PhD student in philosophy at UCSD. My interests are in value theory and moral psychology. My dissertation defends a substantive theory of personal autonomy.