Philosophy
Animal Ethics and the Extension of Moral Considerability
Quick fact
The philosopher Jeremy Bentham argued in 1789 that the key question is not 'Can they reason?' or 'Can they talk?' but 'Can they suffer?'—a criterion that would extend moral considerability to all sentient animals.
Why this is interesting
You probably don't kick a dog for no reason. But have you ever wondered why—what exactly gives that dog a moral claim on you?
Read the full explanation
Understanding Animal Ethics and the Extension of Moral Considerability
Moral considerability is the status of being owed direct moral concern—that is, your interests matter morally in their own right, not merely because of how they affect others. We normally grant this status to human beings, but the question 'why us?' reveals that we are not obviously special. The most influential answer, championed by Jeremy Bentham and later Peter Singer, is sentience: the capacity to experience pleasure and pain. If an animal can suffer, then its suffering matters morally, regardless of its species, intelligence, or usefulness to us. This implies that most vertebrates—and likely many invertebrates—pass the test, while a rock, a plant, or a computer program does not. From this starting point, different ethical theories argue about what we must do: Singer's utilitarianism demands that we minimize total suffering and consider animal interests equally; Tom Regan's rights theory argues that animals are 'subjects-of-a-life' and have inherent rights; and Martha Nussbaum's capability approach holds that animals should be supported in their species-specific flourishing. Though they differ in method, all agree that the boundary of moral concern extends beyond the human species.
A deeper explanation
The mechanism behind extending moral considerability is the recognition that the features we already use to justify moral care for humans—such as the capacity to suffer, the possession of interests, and even a subjective perspective on life—are not unique to humans. Once we accept that these features are what ground moral status, consistency demands that we apply them to any being that possesses them, human or not. This is known as the 'argument from marginal cases': if we grant full moral standing to humans with severe cognitive disabilities who may lack rationality or autonomy, then we cannot refuse it to animals who possess at least similar (or greater) capacities for suffering and flourishing. The exclusion of animals solely because they are not human is called 'speciesism'—a prejudice that Peter Singer likens to racism or sexism, where a morally irrelevant trait (species membership) is used to justify unequal consideration. The practical implications are profound: it challenges factory farming, animal experimentation, and habitat destruction, and it forces us to weigh animal interests in our moral deliberations. The extension of moral considerability is not an all-or-nothing switch; rather, it is a matter of degree—different animals may have varying levels of sentience and cognitive complexity, and thus their interests may weigh differently. Yet the core mechanism remains the same: we must not ignore the suffering of any being capable of suffering.