Moral patienthood (also called moral patience, moral patiency, moral status, and moral considerability) is the state of being eligible for moral consideration by a moral agent. In other words, the morality of an action depends at least partly on how it affects those beings that possess moral patienthood, which are called moral patients or morally considerable beings.
Notions of moral patienthood in non-human animalsLan T, Sinhababu N, Carrasco LR (2022) Recognition of intrinsic values of sentient beings explains the sense of moral duty towards global nature conservation. PLoS ONE 17(10): e0276614. https://doi.org/10.1371/journal.pone.0276614Müller, N.D. (2022). Kantian Moral Concern, Love, and Respect. In: Kantianism for Animals. The Palgrave Macmillan Animal Ethics Series. Palgrave Macmillan, Cham. https://doi.org/10.1007/978-3-031-01930-2_2 and artificial entitiesBalle, S.N. Empathic responses and moral status for social robots: an argument in favor of robot patienthood based on K. E. Løgstrup. AI & Soc 37, 535–548 (2022). https://doi.org/10.1007/s00146-021-01211-2Harris, J., Anthis, J.R. The Moral Consideration of Artificial Entities: A Literature Review. Sci Eng Ethics 27, 53 (2021). https://doi.org/10.1007/s11948-021-00331-8 have been academically explored. More detail on the ethical treatment of nonhuman animals, specifically, can be seen at the Animal rights article.
Definition Most authors define moral patients as "beings that are appropriate objects of direct moral concern". This category may include moral agents, and usually does include them. For instance, Charles Taliaferro says: "A moral agent is someone who can bring about events in ways that are praiseworthy or subject to blame. A moral patient is someone who can be morally mistreated. All moral agents are moral patients, but not all moral patients (human babies, some nonhuman animals) are moral agents."
Narrow usage Some authors use the term in a more narrow sense, according to which moral patients are "beings who are appropriate objects of direct moral concern but are not (also) moral agents". Tom Regan's The Case for Animal Rights used the term in this narrow sense. This usage was shared by other authors who cited Regan, such as Nicholas Bunnin and Jiyuan Yu's Blackwell Dictionary of Western Philosophy, Dinesh Wadiwel's The War Against Animals, and the Encyclopedia of Population. These authors did not think that moral agents are not eligible for moral consideration, they simply had a different view on how a "moral patient" is defined.
Relationship with moral agency
The paper by Luciano Floridi and J.W. Sanders, On the Morality of Artificial Agents, defines moral agents as "all entities that can in principle qualify as sources of moral action", and defines moral patients, in accordance with the common usage, as "all entities that can in principle qualify as receivers of moral action". However, they note that besides inclusion of agents within patients, other relationships of moral patienthood with moral agency are possible. Marian Quigley's Encyclopedia of Information Ethics and Security summarizes the possibilities that they gave:How can we characterize the relationship between ethical agents and patients? According to Floridi and Sanders (2004), there are five logical relationships between the class of ethical agents and the class of patients: (1) agents and patients are disjoint, (2) patients can be a proper subset of agents, (3) agents and patients can intersect, (4) agents and patients can be equal, or (5) agents can be a proper subset of patients. Medical ethics, bioethics, and environmental ethics "typify" agents and patients when the patient is specified as any form of life. Animals, for example, can be moral patients but not moral agents. Also, there are ethics that typify moral agenthood to include legal entities (especially human-based entities) such as companies, agencies, and artificial agents, in addition to humans.Mireille Hildebrandt notes that Floridi and Sanders, in their paper, spoke of "damage" instead of "harm", and that in doing so, they "avoid the usual assumption that an entity must be sentient to count as a patient."
Implications Moral patienthood (or full moral patienthood, in theories which allow for partial moral status) has been alleged (by the cited sources) to imply the following moral obligations:
Stringent presumption against interference: Moral patienthood provides an extremely strong moral reason not to interfere (kill, experiment on, directly cause suffering of) beings that have it; may be overridden only in narrow circumstances. Strong reason to aid: Moral patienthood provides a comparably strong (but weaker than the presumption against interference) reason to provide aid to beings that have it; more easily overridden and does not usually silence other considerations. Strong reason to treat fairly: Comparable interests of moral patients matter equally in distributional choices; gives rise to strong reasons to treat such beings fairly (e.g., equal distribution when appropriate).
Moral patienthood is, by itself, an independent reason to have these moral obligations; there may be other reasons to have these obligations, but merely having these obligations towards a being does not imply that the being is a moral patient. (For instance, supposing that there is a moral obligation to keep promises, someone may acquire these moral obligations toward any being by simply promising to treat it like a moral patient.)
Grounds of moral patienthood Moral patienthood has been claimed, in the literature, to be grounded in various properties. Property Definition Sources Sophisticated cognitive capacities Moral patienthood is grounded in very sophisticated intellectual/emotional capacities (e.g., autonomy, self-awareness, valuing, caring). Kant (Groundwork); Quinn; McMahan; Tooley; Singer; Buss; Theunissen; Feinberg; Jaworska Capacity to develop sophisticated cognitive capacities Potential for such capacities (a "future like ours" or similar) grounds moral patienthood (or some status/enhancement). Stone; Marquis; Harman; Steinbock; Boonin; Feinberg; Wilkins; McInerney Rudimentary cognitive capacities Lower the bar to sentience, interests, basic emotions, or consciousness as sufficient for (full) status. Wood and O'Neill; Regan; Singer; DeGrazia; Rachels; Harman; McMahan; Taylor; Naess; Johnson; Anderson Member of cognitively sophisticated species Moral patienthood via (i) being human or (ii) belonging to any cognitively sophisticated species/kind. Feinberg; Dworkin; Benn; Cohen; Scanlon; Finnis; Korsgaard; Sumner; McMahan; McMahan; Little; Quinn Special relationships Strong reasons (akin to moral patienthood) grounded in species/community, parent–child, or other special ties. Nozick; Scanlon; Kittay; Steinbock; Quinn; Warren; Anderson; Gilbert; McMahan Incompletely realized sophisticated cognitive capacities Having such capacities incompletely realized (via mentor-guided activities/standards) can elevate status (possibly up to full moral patienthood). Jaworska & Tannenbaum Not being designed by anyone to fulfill any purpose The idea that an entity's not having been designed for a purpose grounds being treated as an end (and thus having moral status or some degree of it). Brennan; Katz Naturalness (unaltered by humans) The claim that being natural or unaltered by human intervention confers intrinsic value and thus some moral status. Elliot Harmony and beauty (aesthetic value) of ecosystems Appeals to harmony, beauty, or aesthetic value of ecosystems (or nature generally) as grounds for moral considerability or status. Leopold (A Sand County Almanac); Callicott
Moral weight
Moral weight is a concept used in ethical decision-making to assess the relative significance of the lives, interests, and experiences of moral patients—beings considered to have moral value. It serves as a criterion for determining the extent to which different species should be prioritized in efforts to enhance welfare, based on their capacity for conscious experience, suffering, and wellbeing. Research on moral weight seeks to establish which animals qualify as moral patients and to what degree their interests should be considered, particularly in contexts where resources for improving welfare are limited.
Practical uses
Cost-effectiveness analysis Moral weight is applied to quantify and compare the impact of different charitable interventions. American non-profit GiveWell assigns moral weights to various outcomes, such as increasing consumption versus preventing child deaths, to guide funding recommendations. These weights are based on staff values but are cross-checked with approaches used by governments and global health organizations, such as the "value of a statistical life" metric. While no universal standard exists, most frameworks prioritize childhood over adult mortality prevention. GiveWell's analysis suggests that using standard moral weight assumptions would not significantly alter its current charity recommendations but may influence future evaluations.
Charity prioritization Moral weights help prioritize charities by quantifying the relative value of different interventions, such as reducing mortality, improving health, enhancing mental well-being, and boosting economic circumstances. Founders Pledge uses moral weights to compare the impact of charities operating in these diverse areas. Their approach integrates survey-based methods—considering donor preferences, insights from people in extreme poverty, and expert opinions—with empirical data. This allows them to establish trade-offs between metrics like Disability-Adjusted Life Years (DALYs), WELLBYs, and income doublings. By refining these moral weights, they aim to maximize the effectiveness of charitable giving and identify the most impactful interventions.
Comparing animal welfare Moral weight is a concept used to compare the welfare of different animals, such as chickens, pigs, and octopuses. By examining their behaviors, preferences, and emotional responses, we can understand how intensely they experience pleasure and pain. For example, chickens demonstrate a strong preference for nesting, as seen in their efforts to reach a nest box before laying eggs, suggesting that this activity holds significant importance to them. The recognition of these varying experiences challenges the tendency to underestimate the welfare of non-human animals, and the assessment of moral weight serves as a framework for more ethically informed decision-making in areas such as animal welfare and policy.
Organizations that use moral weight Rethink Priorities uses moral weight to assess animal welfare by calculating each species' potential welfare based on welfare range and lifespan. It assumes utilitarianism, hedonism, valence symmetry, and unitarianism, treating welfare improvements equally across species. By converting welfare changes into DALY-equivalents (Disability-Adjusted Life Years), it enables cross-species cost-effectiveness comparisons, helping to prioritize interventions that maximize overall welfare. Founders Pledge uses the concept to compare the impact of global health and development programs by evaluating different metrics: lives saved, health improvements (DALYs), mental wellbeing (WELLBYs), and economic gains (income doublings). They combine survey-based methods and empirical data to estimate how much each goal matters relative to the others, factoring in perspectives from donors, beneficiaries, and researchers. This approach helps prioritize interventions for maximum impact. GiveWell uses moral weight in cost-effectiveness analyses to compare the impact of different charities, such as those that focus on health improvements versus those that address income.
History