What is a moral patient?

A moral patient is a being that can be wronged and toward which moral agents have duties, even if it cannot itself have duties or act morally; sentient animals and human infants are standard examples.

Why is sentience thought to matter morally?

Because a being that can consciously experience pleasure and pain has interests in how its life goes; many philosophers, following Bentham, hold that this capacity to suffer is what makes a being's interests count morally.

Moral Patiency and Sentience

A moral patient is a being toward which agents can have duties, and sentience, the capacity for conscious experience including pleasure and pain, is the most widely defended ground of moral patiency.

Definition

A moral patient is a being that can be wronged and toward which moral agents bear duties, whether or not it can itself bear duties; sentience is the capacity for conscious experiences such as pain and pleasure, widely held to suffice for the interests that make a being a moral patient.

Scope

This topic covers the distinction between moral agents and moral patients, the case for sentience as the criterion of moral considerability, the principle of equal consideration of interests, and the extension of patiency to non-human animals and other sentient beings. It examines who can be wronged independently of who can do wrong, and connects to debates about the boundaries of the moral community.

Core questions

What distinguishes a moral patient from a moral agent?
Is sentience necessary or sufficient for moral patiency?
Does the capacity to suffer ground a claim to equal consideration of interests?
Which beings beyond humans qualify as moral patients?

Key theories

Sentientism: The view, rooted in Bentham's claim that the question is not whether animals can reason but whether they can suffer, that sentience is the criterion for having morally considerable interests.
Equal consideration of interests: Singer's principle that the like interests of all sentient beings must be given equal weight, so that discounting an interest merely because of species membership is an arbitrary speciesism.

History

Bentham (1789) anchored moral considerability in the capacity to suffer rather than to reason, a line developed in the twentieth century by Singer (1975), who argued from the equal consideration of interests against speciesism, and by Regan (1983), who grounded animal rights in inherent value. The distinction between moral agents and patients has since become central to animal ethics and the ethics of future artificial minds.

Debates

Whether sentience is sufficient or merely necessary: Some hold that sentience alone confers full moral patiency, while others argue that further capacities, such as preferences over time or self-awareness, affect how strongly a patient's interests count.
The agent/patient asymmetry: Because moral patients can be wronged without being able to wrong others, theories grounding morality in reciprocity or agency struggle to accommodate them, motivating non-reciprocal accounts of duty.

Key figures

Jeremy Bentham
Peter Singer
Tom Regan
Lori Gruen

Seminal works

bentham1789
singer1975
regan1983

Frequently asked questions

What is a moral patient?: A moral patient is a being that can be wronged and toward which moral agents have duties, even if it cannot itself have duties or act morally; sentient animals and human infants are standard examples.
Why is sentience thought to matter morally?: Because a being that can consciously experience pleasure and pain has interests in how its life goes; many philosophers, following Bentham, hold that this capacity to suffer is what makes a being's interests count morally.