What are our moral obligations to Earth’s non-human creatures in the Anthropocene Age? The moral issues involved are impossibly complex and ambiguous, but in “Wild Souls: Freedom and Flourishing in the Non-Human World,” American writer Emma Marris tackles the subject head on. This is a compendious, exhaustive book, yet the author’s energy, narrative coherence, and clear prose render the read highly enjoyable and transporting. Drawing on her own global investigations (such a pleasure to read!), on recent and less recent environmental history, and on the clashing philosophical views on the subject, the author delves into the ethical complexities involved. Do we save one animal or do we save a bird species? Can we kill thousands of feral rats to restore environment? Is it better to fight to halt the diminishment of common species or to pull out all stops to arrest an imminent extinction? Do we feed polar bears (a brilliant chapter)? More fundamentally, what is wildness and is any creature now truly wild? Are we conjoined morally with animals or birds or even insects? No breezy diversion, Wild Souls in a welcome in-depth moral re-evaluation that is vital to consider as we face the climate crisis.