In The Moral Circle (2025), philosopher Jeff Sebo calls for a revolution in ethics, arguing that we should expand our “moral circle” to include insects, AI systems, and microbes.
Many legal systems divide the world into “persons,” who have the capacity for legal rights, and “things,” which lack this capacity. (1)
[We] classify humans (and entities representing human interests, like corporations) as persons and everyone and everything else as things. (1)
The moral circle [is] the set of beings who matter for their own sakes. (2)
Which kinds of beings can be members of the moral circle, and why? (3)
Does every member of the moral circle matter equally, or do some (say, members of our nation, generation, or species) matter more? (3)
Does every member of the moral circle matter in the same kind of way, or do some (say, beings with advanced language and reason) matter in different kinds of ways? (3)
How we draw the moral circle during our time in power might affect how AI systems draw the moral circle during their time in power. (5)
At least in the West, the history of thinking about the moral circle has been one of moral circle expansion. As a general trend, we started with highly exclusionary views, because we overestimated what it takes to matter and underestimated who has what it takes to matter. (5)
Many experts previously believed that only rational beings matter, but [they] now believe that all sentient beings matter. Similarly, many experts previously believed that only vertebrates can be sentient, but [they] now believe that many invertebrates can be sentient. (5)
We are increasingly creating beings, including both animals and AI systems, who at least might be morally significant. (6)
You count as sentient when you can experience positive states like pleasure or happiness or negative states like pain or suffering. (15)
The scientific evidence now supports attributions of consciousness to all mammals and birds, as well as “at least a realistic possibility of consciousness” in “all vertebrates (including all reptiles, amphibians, and fishes) and many invertebrates (including, at minimum, cephalopod mollusks, decapod crustaceans, and insects).” (65)
Our moral faculties are outdated. We perceive the direct effects of small-scale interactions as morally significant much more easily than the indirect effects of large-scale interactions. (99)
If there is any chance at all that our actions are helping or harming particular beings, then this possibility merits consideration. (136)
Book Notes
There is no moral circle. We love the idea of a well-ordered moral universe. But it’s a fantasy. There is no clear boundary or hierarchy. We aren’t even internally consistent.
Forty percent of us would save our cat over a stranger. It’s normal to love dogs, eat pigs, and wear cows. We demand climate action, yet we cling to our cars or hot showers or air conditioners. We divide people by category (e.g., race, ethnicity, citizenship, sex, gender, sexual orientation, criminal record, mental health, politics, religion, education, occupation, age, class, wealth, disability). Our ethics are riddled with idiosyncrasy and hypocrisy.
As I explain in Animals Are People, morality is a multi-spectral mess that we simply can’t make sense of; so it’s fair to say that a “moral polygon” is a more honest mental model — although to frame it as the moral megagon may prove to be more sticky.
Who am I kidding? We believe what we want. The ideal of a moral circle makes us feel good. So why give that up for an ugly, uncomfortable shape? — even if it is the truth.
As I work on Natural Information Architecture, I’m sharing notes and quotes from my sources of inspiration and provocation. As always, your questions and suggestions are welcome.