Throughout human history, the scope of justice has gradually expanded. Moral responsibility once applied in family or tribe, then it extended to nations, races, genders and eventually all human beings through the groundbreaking declaration of universal human rights by the United Nations General Assembly in Paris on 10 December 1948. However, what naturally follows such logic is an ethical question that remains unresolved: should the expansion of moral circle reach non-animals? Albert Schweitzer challenges modern society to reconsider the boundaries of moral concern by stating, “Until he extends the circle of his compassion to all living things, man will not himself find peace.” Applying both human logic and emotion, there is no reason to object to this statement.
Compassion represents the moral ability to recognize the suffering of others and respond with care and restraint. Peace is not simply the absence of conflict, but a deeper harmony between human actions and social principles.
Moral progress that centers on compassion and aims for peace is incomplete as long as humanity continues to ignore the suffering of other sentient beings. While some critics argue animals can’t possess rights due to lack of rationality or moral agency, the capacity for suffering and the inherent value of animal life justify expanding justice beyond humanity.
One of the most influential objections to animal rights is based on the idea that rights belong only to rational moral agents. Animals cannot possess rights because they lack intellectual and moral capacities necessary to participate in ethical systems. Philosopher Carl Cohen defends this position by defining rights as moral claims that only human beings can assert against other species. As he emphasizes, rights belong to beings who are capable of understanding moral duties and recognizing conflicts between personal interests and justice. This explains why he holds the sociological view that “holders of rights must have the capacity to comprehend rules of duty and recognize possible conflicts between what is in their own interest and what is just.” 1 Because animals cannot understand moral rules or make ethical claims, Cohen concludes that they can’t possess rights.
At the same time, social contract theorists such as Jan Narveson argue that morality arises from agreements between rational individuals who seek mutual benefit.2 Under this framework, rights exist only within a community of rational agents capable of cooperation and negotiation. Animals can’t participate in such agreements and hence they are outside the moral contract that generates rights. Both human centered philosophers characterized by Carl Cohen and sociologists led by Jan Narveson highlight rationality as the foundation of morality. If rights depend on moral reasoning and participation in ethical communities, then animals indeed seem excluded by definition. However, closer examination reveals serious problems with this reasoning:
Modern scientific research increasingly challenges the assumption that animals lack the cognitive and emotional capacities required for moral consideration. Studies in animal behavior and neuroscience demonstrate that many species possess complex forms of intelligence, memory and emotional awareness. Research published in the 2012 Cambridge Declaration on Consciousness concluded that numerous non-human animals, including mammals, birds, and even some invertebrates, possess the neurological substrates necessary for consciousness. 4 Similarly, experiments with primate and dolphins have shown evidence of self-recognition in mirror tests, a trait often associated with self-awareness. Statistical observations in behavioral studies also reveal that animals exhibit long-term memory, problem solving abilities and social cooperation.
These scientific findings strongly support the philosophical argument made by philosopher Tom Regan. He states that because animals have an individual life that matters to them, they hold inherent value and should not be treated merely as means to human ends. If we adopt Regan’s, we must accept that animals are not mindless being’s as earlier philosophers believed. Research in animal cognition has revealed that many species display complex behaviors, emotional response and even forms of problem-solving. Regan argues that animals are “subjects-of-a-life.” 3 This is to say, animals possess belief, desires, perceptions, memories and therefore an understanding of their own welfare. Because animals experience their lives from their own perspective, they have inherent value that does not depend on their utility to humans.
If animals are indeed subjects of a life with their own preferences and experiences, their interests cannot be dismissed as morally irrelevant. A growing body of scientific evidence, strengthens Regan’s philosophical argument that animals possess inherent value and deserve moral consideration beyond their utility to humans. In this sense, empirical research and ethical theory have disproved the traditional assumption that moral concern should be limited exclusively to humanity.
Even if rationality was considered a requirement for rights, a loophole in such a judgement leads to problematic marginal cases. Certain categories of human, such as infants, people with severe cognitive disabilities, or those in comas, lack the advanced rational capacities emphasized by Cohen and Narveson. Yet society clearly recognizes that these individuals still possess rights and deserve moral protection. If rationality was truly the basis of rights, then these vulnerable human beings would also be excluded; and this is clearly an inhumane statement that would be deemed unacceptable by most. Therefore, rationality alone cannot serve as the defining criterion for moral status, as it is contradictory in itself.
Utilitarian philosophers such as Peter Singer argue that the relevant factor is not intelligence but the ability to suffer. If suffering is morally significant for humans, it must also matter when experienced by animals. To treat similar suffering differently merely because of species membership would be morally inconsistent. Singer emphasizes that what matters morally, is the ability to feel pleasure and pain. He criticizes “speciesism”—the belief that humans automatically deserve greater moral value simply because they are human—and this naturally leads to the conclusion that “all beings with interests, capable of enjoyment or suffering, deserve to have those interests taken into account in moral decision making.”5 This reasoning undermines the claim that animals can be excluded from moral consideration simply because they lack human-like reasoning abilities.
Beyond philosophical arguments, the long-lasting expansion of moral concern that defines humanity provides further support for extending compassion toward animals.
Historically, many groups were once denied moral recognition. Slavery, colonial domination and even gender inequality were all justified by legal and cultural codes with the outdated intellectual inferiority or natural hierarchy. However, over time, societies gradually rejected these justifications and recognized the equal moral worth of all human beings. Some, animal rights theorists, such as Gary L. Francione, focus on how laments that animals continue to be treated primarily as property rather than as individuals with inherent value. I find this an important point. When animals are legally defined as property, their interests can always be overridden by human desires. Francione writes that because animals are considered property, “their interests are not protected for their own sake; their value is whatever their owners assign to them.”6
This legal and moral structure allows the large-scale exploitation of animals for food, entertainment, and research, even when these uses are unnecessary. Francione argues that genuine moral progress requires recognizing animals as beings with their own interests rather than merely as resources. If different humans of different ethnicities genders and ages win their dignity because of self-worth and sentience, what do animals lack to be deprived of such rights? Focusing on this perspective, extending moral concern to animals represents the next stage in the historical expansion of justice. Just as earlier generations widened the moral circle to include previously excluded humans, contemporary society faces the challenge of recognizing the moral significance of animal life.
Revisiting Schweitzer’s statement, we can now see its deeper ethical significance. The “circle of compassion” represents humanity’s evolving moral awareness. Each time the circle expands, it reflects a greater recognition of the suffering and dignity of others. When humans ignore the suffering of animals, they create a moral contradiction: a society that values compassion and justice simultaneously bring large-scale harm to similarly sentiment beings. Moral progress is not only defined as technological advancement or political power, but also the ability to recognize the value of life itself. True compassion reflects a deeper understanding that humanity does not exist apart from the natural world but within a shared community of living beings. Recognizing animals as morally considerable beings then represents a continuation of its historical development. The idea of peace is not merely personal tranquility but broader ethical harmony in a world achieved when human practices align with principles of compassion and justice.
The debate over animal rights ultimately challenges the foundations of moral responsibility. While critics argue that rights belong only to rational moral agents, this position becomes difficult to defend when confronted with both scientific evidence of animal cognition and philosophical argument about suffering and moral consistency. Ethical responsibility has expanded as humanity learns to recognize vulnerability, suffering and the intrinsic value of life. A society that limits compassion only to those most similar to itself risks reducing ethics to convenience rather than principle. If moral concern depends solely on rational ability or species membership, then justice becomes a reflection of power rather than a commitment to fairness. The question raised by animal rights therefore extends beyond policy or law; it asks whether humans are willing to apply moral ideals consistently. True moral progress lies in the willingness to extend concern beyond boundaries. By widening the circle of compassion, humanity does not diminish its moral identity; instead it deepens it, moving closer to an ethic grounded not in domination over life, but in responsibility toward it.
1 https://www.jstor.org/stable/2265074
2 https://link.springer.com/chapter/10.1007/978-1-4612-5623-6_3 (Cited from Jan, Narveson Animal Rights Revisited)
3 Cited from The Case for Animal Rights
4 https://docslib.org/doc/8110408/the-cambridge-declaration-on-consciousness
5 Cited from Animal Liberation
6 https://law.bepress.com/rutgersnewarklwps/art21/