De Waal (1996) claims that all of the essential ingredients of morality can be found within the animal kingdom, especially in primate societies. He identifies four crucial features:
(i) sympathy-related traits, including nurturance (care of one's own offspring), succorant behaviour (common in mammals: caring for individuals other than one's progeny, being emotionally affected by their suffering, and learning to adjust to their needs), and in the case of the great apes, cognitive empathy (the ability to understand other individuals' suffering by putting onself in their position, and extrapolating what they would be able to do);(ii) norm-related characteristics such as: active inculcation of rules by parents, grading of punishments depending on the age of the individual, the tailoring of instructions to the learner's level of experience; and conflict mediation by leaders;
(iii) reciprocity, manifested in behaviour such as reciprocal altruism and "tit-for-tat" co-operation strategies; and
(iv) the ability of animals to get along with each other by reining in their aggressive responses, reconciling after fights and accepting third-party mediation.
While I acknowledge that these features are among the building blocks of morality, I maintain that taken together, they fail to satisfy even the most basic definition of morality. There are several features that moral agents need to possess, which non-human animals probably lack.
Moral norms
First, we cannot speak of morality in non-human animals unless parents can transmit moral norms to their offspring. Regardless of whether moral norms can define what it is to act morally (as some act-centred moralists would maintain), it is uncontroversially true that following moral norms is a vital part of learning how to do what is right.
Hierarchical animals such as canids and primates transmit social rules to juvenile members of their groups; monkeys even grade punishments for offences according to the age of the individual (De Waal, 1996). However, there are good reasons for questioning whether this can be described as instilling a moral norm. The juvenile animals described by De Waal (1996) who learned to conform to the "norms" of their group may have been simply avoiding unpleasant consequences, like the fly in chapter two that learned to adjust its yaw torque to escape a heat beam - the only significant difference being that in the primate case, the adverse consequences are enforced by the other animals in its group, whose "punishing behaviour" may simply be motivated by an innate or acquired dislike of the behaviour of the offending individual, or a learned association between the individual's behaviour and some bad consequence for the group.
The distinction between following a rule and avoiding a bad consequence may seem to be a blurred one: after all, some people follow moral rules simply because they fear the bad consequences of breaking them. However, the vital difference is that a rule-follower understands that what causes the bad consequence is not the offending act itself, but the rule-enforcer's discovery of the act, coupled with her attribution of it to the offender - which is why criminals often try to cover up evidence of their deeds, and why an offender accused of committing a crime may lie or blame someone else. The act of following a rule therefore requires an individual to possess a human-like theory-of-mind, and be able to attribute to other individuals not only beliefs, but mistaken beliefs about other agents ("I won't get caught if she thinks someone else did it"). Even for chimpanzees, the evidence for such an ability is highly questionable at best (Hauser, Chomsky and Fitch, 2002; Nissani, 2004; Emery and Clayton, 2004).
"Mental time-travel"
Of all the metaphors we use to describe morality, perhaps the most ubiquitous is that of the path. Buddhists talk of an eight-fold path; Taoists talk of "the Way"; and in our own culture, the metaphor of "staying on the straight and narrow" is a familiar one. The insight behind this metaphor is a rich one: a moral agent must be capable of evaluating and improving her conduct over the entire course of her life. To do this, she must possess an extraordinarily "thick" concept of time: she has to be able to recall her past actions in a temporal sequence, looking for signs of either progress or back-sliding, and formulate resolutions to improve her conduct in the future. An individual that lacked the ability to reflect on her past and future life would be morally paralysed, unable to diagnose her character faults or resolve to rectify them. In other words, moral agency requires not only an episodic memory, which some birds may possess in a rudimentary form (Emery and Clayton, 2004), but an autobiographical memory, which makes "mental time-travel" possible. Autobiographical memory is generally acknowledged to be a human specialty (Tulving, E. 2002. "Episodic memory and common sense: how far apart?" In Episodic Memory: New Directions in Research. Edited by Baddeley A., Conway M. and Aggleton J. New York: Oxford University Press. pp. 269-288). Other domains in which non-human animals can perfect their abilities (e.g. their motor skills) do not require them to possess such a rich form of memory.
The ability to cultivate dispositions and attitudes
Part of the reason, I would suggest, why some people feel a residual inclination to ascribe moral agency to animals is that they possess temperamental traits (e.g. the placidity of a Golden Retriever) which superficially resemble morally virtuous dispositions acquired by human beings. But as Hursthouse (2003) notes, virtuous dispositions are far deeper and richer than ordinary dispositions:
A virtue such as honesty or generosity is not just a tendency to do what is honest or generous, nor is it to be helpfully specified as a "desirable" or "morally valuable" character trait. It is, indeed a character trait - that is, a disposition which is well entrenched in its possessor, something that, as we say "goes all the way down", unlike a habit such as being a tea-drinker - but the disposition in question, far from being a single track disposition to do honest actions, or even honest actions for certain reasons, is multi-track. It is concerned with many other actions as well, with emotions and emotional reactions, choices, values, desires, perceptions, attitudes, interests, expectations and sensibilities. To possess a virtue is to be a certain sort of person with a certain complex mindset. (Hence the extreme recklessness of attributing a virtue on the basis of a single action.) (Hursthouse, Rosalind, "Virtue Ethics", The Stanford Encyclopedia of Philosophy (Fall 2003 Edition), Edward N. Zalta (ed.), Web address: http://plato.stanford.edu/archives/fall2003/entries/ethics-virtue/.)
The possession of appropriate attitudes towards morally significant individuals is an important part of the "complex mind-set" presupposed in morally virtuous behaviour. It is tempting to suppose that non-human animals could possess these attitudes implicitly, and that they might acquire them simply by following the example of role models in their group, even in the absence of language. However, this supposition overlooks two significant features of our moral attitudes: we can critically evaluate our own attitudes; and we can attempt to inculcate virtuous attitudes in other individuals. Unless animals can exercise these capacities, it is hard to see how their attitudes could be justifiably deemed "moral" or "immoral". One could hardly fault an animal for the "bad attitudes" it picked up simply from following its role models, if it lacked the cognitive apparatus for questioning its own attitudes, or correcting those of another individual. Both of these tasks can only be caried out on an explicit level. An example by Midgley (1984) of how parents typically instil moral attitudes illustrates this point perfectly. The case Midgley considers is that of parents who find their small children tormenting animals:
We say, "you wouldn't like that done to you", and I do not think that this is a Father Christmas case of deliberate deception. We mean it (1984, p. 91).
Although the parent is trying to change the child's conduct, the focus of the reproof is on the child's mental attitudes: transforming the child's whole way of thinking about other animals becomes the means by which the change in conduct is brought about. The task of getting another individual to focus on his mental attitudes requires a high degree of abstraction, and "language" in the "narrow" sense described by Hauser, Chomsky and Fitch (2002) - made possible by what the authors call the recursive faculty, which can allows language-users to generate a potentially infinite variety of sentences - appears to be the only medium of communication that is rich enough to allow its users to refer to each other's attitudinal concepts, criticise each other's bad attitudes and instil new moral norms, in an limitless variety of ways.
If the foregoing arguments are correct, then we are unlikely to ever discover instances of moral agency in non-human animals.