An Ape Ethic and the Question of Personhood proposes that differences between humans and apes provide the foundation for the call to recognize forest personhood in the great apes. While all ape species are alike in terms of cognition, intelligence, and social behaviors, great apes, not humans, are efficient ecosystem engineers.

_Evolution and Human Culture_ surveys disciplines of evolutionary studies to posit that hominin evolved moral sentiments have been integral to the development of artistic culture.