About

Samuel C. Rickless is the Distinguished Professor of Philosophy and chair of the UC San Diego Department of Philosophy. His research interests include the history of European philosophy, with emphasis on figures such as Plato, René Descartes, John Locke, Mary Astell, George Berkeley, David Hume, and Mary Shepherd. He also focuses on moral philosophy, particularly non-consequentialist ethics based on the doctrine of doing and allowing and a secular version of the doctrine of double effect, as well as legal philosophy, including issues of legal interpretation, the right to privacy, due process, and equal protection under the Fourteenth Amendment of the U.S. Constitution. Additionally, his work encompasses the philosophy of language and experimental philosophy, notably through his involvement with the Moral Judgments Project, which collaborates with philosophy and psychology scholars on research in experimental philosophy.

Research topics

• Epistemology
• Psychology
• Social psychology
• Statistics
• Mathematical economics
• Economics
• Mathematics
• Philosophy

Selected publications

• The Moral Status of Enabling Harm Revisited

  Pacific philosophical quarterly · 2026-01-15

  article1st authorCorresponding

  ABSTRACT Most non‐consequentialists accept that, other things equal, it is more difficult to justify doing harm than it is to justify allowing harm . But there is a further question regarding the moral status of enabling harm. Rickless (2011), following in the footsteps of Foot (1967) and Hanser (1999), has defended the moral equivalence of enabling harm and allowing harm (MEEA). His case for MEEA, as well as MEEA itself, has been criticized by Barry and Øverland (2016), as well as by Lippert‐Rasmussen (2015). In this essay, I revisit this controversy and argue that MEEA and the existing arguments for it withstand all of these criticisms.

  PublisherDOI

• Why Mary Astell's Theory of Virtue is Not Inconsistent

  Locke Studies · 2025-12-21

  articleOpen access1st authorCorresponding

  There is an apparent inconsistency at the heart of Mary Astell’s theory of virtue, for she seems committed to contradictory propositions: (1) that virtue involves alignment of all passions with their proper objects; and (2) that virtue involves the elimination or extirpation of at least some passions, such as pride, anger, hatred, and overwhelming sorrow. Jacqueline Broad (2015) has tried to solve this interpretive problem by suggesting that Astell recommends a two-step process for the virtuous management of one’s passions, with (1) occurring first and in the short term and (2) occurring second and in the long term. This essay agrees with Broad that Astell does not fall into inconsistency, but for different reasons. It argues that Astell consistently treats self-esteem, anger, hatred, and sorrow as unmoralized (i.e., neither virtuous nor vicious) passions that cannot, and hence should not, be extirpated, but that vicious forms of these passions, such as in the case of pride and overwhelming sorrow but also in the case of excessive anger and hatred, should be removed from the soul through proper redirection and adjustment in both the short term and the long term.

  PublisherOA PDFDOI

• Does Sarah Chapone Endorse a Republican Conception of Liberty?

  European Journal of Philosophy · 2025-07-15

  articleOpen access1st authorCorresponding

  Abstract In The Hardships of the English Laws in Relation to Wives (1735), Sarah Chapone argues that the English laws governing marriage, including the common law doctrine of coverture, are cruel and unjust to wives. In a close study of this work, Jacqueline Broad (2015) argues that Chapone endorses a republican (or nondomination) conception of liberty, as the absence of anyone else's arbitrary, non‐normative power to intentionally worsen one's choice situation without tracking one's own needs and interests with respect to matters of importance in one's life. In this essay, I argue that Chapone is better read as a rights‐based moral theorist who argues that English laws are unjust by virtue of the fact that they give husbands (not the non‐normative power but) the legal authority to violate the moral rights of their wives, and otherwise do not protect wives from being wheedled, coerced, or manipulated into giving up that to which they have a moral right. This picture is consistent with a non‐republican understanding of liberty as the absence of interference rather than as the absence of domination.

  PublisherOA PDFDOI

• Does Mary Astell think that marriage is a form of slavery?

  British Journal for the History of Philosophy · 2025-06-16

  article1st authorCorresponding
  PublisherDOI

• Locke on Consent, Societal Membership, and Political Obligation

  History of Philosophy Quarterly · 2025-04-01

  articleOpen access1st authorCorresponding

  Abstract There are two main theories of how express consent and tacit consent determine societal membership and political obligation in Locke's political philosophy. On the “Serious Stake” interpretation, all and only those who have a stake in the community (including some who only tacitly consent to membership) are members of society. On the “Express Consent” interpretation, all and only those who expressly consent to be or become members are members, and tacit consent determines political obligation. This essay articulates a version of the Express Consent interpretation on which express consent to X is given by means of conduct that has semantic meaning sufficient to count as agreement to X. It then explains how this interpretation can meet standard objections to the Express Consent interpretation while avoiding the serious textual problems that face the Serious Stake interpretation.

  PublisherOA PDFDOI

• The Parmenides

  2024-10-01

  book-chapter1st authorCorresponding

  Plato’s Parmenides is a notoriously challenging dialogue. Scholars have struggled mightily to provide us with a satisfying interpretation of its philosophical content and purpose. In this chapter, I will summarize what I take to be the best interpretation and defend it against some recent challenges and alternative proposals.

  PublisherDOI

• Non-consequentialist principles under conditions of uncertainty

  Cambridge University Press eBooks · 2023-02-24 · 1 citations

  book-chapterSenior author

  We explore whether there is a plausible probabilistic version of the Doctrine of Double Effect (DDE), and more generally pursue the question of how probabilistic outcomes affect the application of moral principles. Many think that the DDE helps explain why it is permissible to shunt a trolley onto a sidetrack to which one person is tied (thereby resulting in his death) in order to save the lives of five people tied to the main track, whereas it is impermissible to lead an unsuspecting person onto the main track in order to save the five. But we can ask: Does it make a difference if we have an option to lead a person onto the main track when there is only a small to moderate chance that he will be killed? Here we make a start toward an answer by investigating why it is generally wrong to risk harm to others, taking as a defeasible starting point a pluralistic deontological account of morality. In the process, we explore whether imposing risk is causing harm, how to sort permissible from impermissible risk impositions, and why we should not expect a linear function between degree of risk imposed and seriousness of wrong.

  PublisherDOI

• Beyond killing one to save five: Sensitivity to ratio and probability in moral judgment

  Journal of Experimental Social Psychology · 2023 · 6 citations

  Senior authorCorresponding
  • Psychology
  • Social psychology
  • Epistemology

  A great deal of current research on moral judgments centers on moral dilemmas concerning tradeoffs between one and five lives. Whether one considers killing one innocent person to save five others to be morally required or impermissible has been taken to determine whether one is appealing to consequentialist or non-consequentialist reasoning. But this focus on tradeoffs between one and five may obscure more nuanced commitments involved in moral decision-making that are revealed when the numbers and ratio of lives to be traded off are varied, and when the probabilities of each outcome occurring are less than certain. Four studies examine participants' reactions to scenarios that diverge in these ways from the standard ones. Study 1 examines the extent to which people are sensitive to the ratio of lives saved to lives ended by a particular action. Study 2 verifies that the ratio rather than the difference between the two values is operative. Study 3 examines whether participants treat probabilistic harm to some as equivalent to certainly harming fewer, holding expected ratio constant. Study 4 explores an analogous issue regarding the sensitivity of probabilistic saving. Participants are remarkably sensitive to expected ratio for probabilistic harms while deviating from expected value for probabilistic saving. Collectively, the studies provide evidence that people's moral judgments are consistent with the principle of threshold deontology.

  PublisherDOI

• Trolley Problems Reimagined

  2023-07-19 · 1 citations

  book-chapter

  This chapter considers two ways in which traditional approaches to testing lay moral theories have oversimplified our picture of moral psychology. One oversimplification is to sort instances of reasoning into an implicit consequentialism or an absolutist non-consequentialism. Prior research by the authors reveals another option that people appeal to threshold deontology, a non-absolutist version of non-consequentialism according to which rights sometimes override the maximization of consequences, but not always. This chapter explains why varying questions on surveys in certain ways leads to a more nuanced and truer picture, and briefly explores the implications of that research. The chapter then turns to a second way in which asking a different kind of question can bring out a fuller picture of implicit moral theorizing, by considering several studies that ask participants comparative questions that involve not just comparing acting in such a way that there is a risk of killing vs. allowing to die, but how the risk is distributed. Asking the comparative question offers intriguing results that contrast with those that emerge from asking non-comparative questions. The chapter then considers the challenging methodological question of whether results should be privileged based on one way of asking the questions over the other.

  PublisherDOI

• Berkeley and Shepherd

  Oxford University Press eBooks · 2022-02-14

  book-chapter1st authorCorresponding

  Abstract This chapter analyzes and evaluates criticisms of Berkeley’s arguments for idealism and theism offered by Shepherd. In the Principles, Berkeley argues that sensible objects (such as tables and chairs) are perceived by sense, that the things we perceive by sense are ideas, and hence that sensible objects are ideas. He also argues that God is the only possible cause of our ideas of sense. Shepherd criticizes both of these arguments. Although most of her criticisms (particularly in the case of Berkeley’s reasons for believing in the existence of God) are unsuccessful, her main strategy in finding fault with Berkeley’s argument for idealism, which involves identifying various ways in which he is guilty of equivocation, is sound.

  PublisherDOI

Frequent coauthors

• Dana Kay Nelkin

  16 shared

• Arseny A. Ryazanov

  University of California, San Diego

  4 shared

• Craig R. M. McKenzie

  3 shared

• Shawn Tinghao Wang

  2 shared

• Nicholas Christenfeld

  University of California, San Diego

  1 shared

• Jonathan Cohen

  University of Oxford

  1 shared

• Leonardo Moauro

  1 shared

• Jonathan Knutzen

  New York University

  1 shared

Education

• Ph.D., Philosophy

  University of California Los Angeles

  1996

• B.Phil., Philosophy

  University of Oxford

  1988

• B.A., Philosophy

  Harvard College

  1986