During the interview, the question arises of whether apes are 'moral beings'. De Waal thinks they're not, but it's more complicated than that:
SPIEGEL: They're unlikely to be familiar with the categorical imperative.The (convincing) argument that 'reciprocal altruism' has been one of the main motors in the development of human morality has been most importantly developed by Robert Trivers. It is not, though, the only one.
De Waal: But they are. They're very familiar with the motto "Do unto others as you would have them do unto you." It's precisely the principle of reciprocity that I see, in addition to empathy, as the fundamental element in the psychology of all primates. We did an experiment in which we gave chimpanzees watermelons and then documented how they divided up the fruit among themselves. In the hours leading up to the experiment, we recorded which animals groomed which other animals' fur. The results were clear. The ape that divided up the watermelon gave significantly more to those apes that had groomed him earlier on.
SPIEGEL: You also mentioned empathy...
De Waal: Oh yes. For example, chimpanzees are quite good at comforting one another. If a friend is suffering, they hug him and attend to him. It's only our arrogance that makes us doubt that this is even possible. When someone brutally kills someone else, we call him "animalistic." But we consider ourselves "human" when we give to the poor.
SPIEGEL: On the other hand, the philosopher Thomas Hobbes said: "Homo homini lupus," or "man is a wolf to man."
De Waal: The evolutionary struggle for survival is really a self-serving series of blows and stabs, and yet it can lead to extremely social animals like dolphins, wolves or, for that matter, primates. I call the notion that we are nothing but killer apes the Beethoven fallacy. Beethoven was disorganized and messy, and yet his music is the epitome of order.
Peter Singer's development and discussion of the evolution of ethics - involving, in his view, kin selection, reciprocal altruism, empathy, group selection (which, I know, is controversial among evolutionary theorists) and reason - effectively summarises some of the issues involved (though I think he's rather too harsh on poor old Hobbes in this context).
(The article linked to here doesn't really get to the bits about reason and empathy, which come later in his book The Expanding Circle: Ethics and Sociobiology (New York, 1981). I am, moreover, aware that there are problems with Singer's philosphical perspective and limits to his utilitarian ethical outlook; nevertheless, I find that this book is very good.)
What follows, I think, is an important likelihood: rather than having a single basis, morality and ethics are derived from a variety of different sources. This suggests that human ethics, instead of being something which developed whole cloth based upon a single principle, are distinctly situational: the kinds of mental calculus that people use in connection with family members are likely different than those applied to strangers. And for good reason. Thus, elaborate, all-purpose ethical systems based upon a single notion - be it reason, utility or biology - will, by definition be incomplete. (Nonetheless, evolutionary theory also, in my view and contrary to what is commonly assumed, offers the rather encouraging notion that there is, in fact, some kind of deeply-ingrained ethical intuition with regard to some situations, at least on a very basic level.)
I can't think any further than this, though, at the moment. Not on a Monday. When it's raining.