Primates and Philosophers, or how you should think of morality on the 21st century. This could as well be the title of this book. For, as de Waal states in the conclusion of this work "The debate with my colleagues made me think of Wilson’s (1975: 562) recommendation three decades ago that 'the time has come for ethics to be removed temporarily from the hands of philosophers and biologicized.'" (2006) So there you have. You can either go by the moralists who believe that morality is only a human affair, or go the biological way and realize that as with everything else, in what concerns morality, we are again the tip of the iceberg in evolutionary terms.

If you are interested in delving deeper into these kind of debates, you'll definitely love this book. There's plenty of academic nitty-picking inside, so you have to measure how much committed you are to these issues before opening the book. Again, quoting de Waal, "While making for good academic fights, semantics are mostly a waste of time. Are animals moral? Let us simply conclude that they occupy several floors of the tower of morality. Rejection of even this modest proposal can only result in an impoverished view of the structure as a whole" (2006).

In any case, de Waal's essays are rich and insightful as everything he has written thus far. So you won't waste your time if you just read his contributions to the volume.