Through case studies on captive elephants, farmed insects, and the ethical dilemmas of creating digital minds, Sebo explores how expanding the moral circle could transform society.

The book stresses the importance of acknowledging uncertainty and disagreement about the boundaries of the moral circle, especially as human actions increasingly impact a wide range of beings, including those that are often overlooked, such as insects, microbes and potential future AI entities.

Throughout the book, Sebo highlights the need to develop new moral frameworks that address the complexities of existence and the diverse range of beings with which humans share the world.

He urges caution and humility in approaching these ethical discussions, suggesting that many beings may matter morally and deserve consideration and care.

King highlights its use of thought experiments to encourage broader empathy, while American ecologist and author Carl Safina acknowledges its challenge to conventional ethical boundaries, suggesting that its arguments may prompt discomfort but also critical reflection.

The review highlights Sebo's argument for expanding moral consideration to encompass animals, insects, plants, microbes, and artificial intelligence, challenging the notion of human exceptionalism.

However, Marshall questions whether Sebo's argument is timely, given ongoing struggles for human rights, though he ultimately acknowledges that calls for greater empathy may be more necessary than ever.