This work investigates whether moral agency is an exclusively human trait or if non-human animals possess the capacity for ethical behavior. Stephen R. L. Clark, a philosopher specializing in animal rights and classical thought, utilizes a combination of evolutionary biology, ethology, and moral philosophy to challenge the anthropocentric view of ethics. He argues that the divide between human morality and animal instinct is less distinct than traditional philosophy suggests, proposing that social cooperation and altruism in animals serve as precursors to human moral systems.

Experts in the field of animal ethics recognize this text as a significant contribution to the debate on moral status and cognitive capacity. Readers frequently note the academic density of the prose, which requires a foundational understanding of philosophical terminology to fully grasp the author's arguments.