Expanding the Moral Circle: Including More Animals in Our Ethical Consideration

The history of moral progress can be understood as an expansion of the moral circle. Understanding how this expansion occurs helps advocates think about how to extend it to more animal species.

Key Facts

Philosopher Peter Singer popularised the concept of the expanding circle applied to animal welfare in the 1970s
Historical moral circle expansions include the abolition of slavery, womens suffrage, and disability rights
Sentience — the capacity to suffer and experience — is the most widely accepted criterion for moral inclusion
Research on invertebrate cognition is challenging assumptions about which animals warrant moral consideration
The Cambridge Declaration on Consciousness in 2012 affirmed that many non-human animals possess consciousness
Legal personhood for some animals is being argued in courts in several countries as a form of moral circle expansion

Welfare Considerations

Expanding the moral circle to include more animals is both an ethical and a practical challenge. Historically, moral circle expansions have been driven by evidence, argument, and empathetic connection. For animals, evidence of sentience and cognitive complexity is growing rapidly, strengthening the factual basis for inclusion. However, moral circle expansion also requires overcoming economic interests, cultural traditions, and in-group bias. Advocates who understand both the philosophical arguments and the social dynamics of moral progress are better positioned to accelerate this expansion effectively.

What You Can Do

Engage with the philosophical arguments for animal moral consideration through Peter Singer and others
Share evidence of animal sentience and cognition with audiences who may not have encountered it
Support legal personhood campaigns for cognitively complex animals such as great apes and elephants
Explore effective advocacy strategies for moral circle expansion through Animal Charity Evaluators
Connect animal welfare arguments to other moral circle expansions to build bridges with social justice advocates