ABSTRACT If we accept that the behaviour of humans and other animals is very substantially channelled by evolutionary constraints, it might appear that there can be no place for animals within the protection of a human system of morality. However, the nature of plausible evolutionary constraints on the cognition of social animals, including humans, suggests that this is not so. It is likely that the most important element in our morality is the capacity to imagine the feelings of other individuals, (...) and this capacity is so important for our ability to understand and predict their behaviour that it would be likely to be preserved by evolution even if moral behaviour had no survival value in its own right. We also use this kind of imaginative sympathy to understand and predict the behaviour of other animals, and it is this which provides the main reason for the inclusion of such animals within a human moral system. The primitive elements of morality have a survival value that is probably common to many other social species of animals. Since one of our reasons for putting a special value on human life is the human capacity for moral behaviour, we ought also to view members of these species as being of special significance. (shrink)