All animals have neighbours of their own kind. In some species, neighbours rarely meet (except during the breeding season), and are indifferent to one another. In others, neighbours are rivals or competitors, and interactions are brief and hostile. There are many species, however, where individuals pass most of their lives as members of flocks or herds, and are profoundly influenced by their social environment. They may, indeed, pursue their own selfish interests to the best of their ability, but they cannot afford to be entirely indifferent or hostile to the rest of the herd.
Sometimes this social cohesion is of the simplest kind, as in shoals of fish that band together for mutual protection against predators. Sometimes it involves a complex division of labour into distinct castes with a range of social roles, as in the colonies of ants and termites. Even bacteria can form communities in which different types make distinctive contributions to the well-being of the community as a whole. By far the most elaborate societies, of course, are formed by people living in cities. Our whole social and economic life is made possible only by a finely-chopped division of labour in which each person performs only some narrowly circumscribed task, and relies for most of the necessities of life on the activity of a multitude of neighbours. This is made possible only by the trust of strangers, in the memorable phrase of one of the participants in this symposium.
In other words, our unique social and economic system is underpinned by an ethical system that leads us to rely on the support and cooperation of other individuals, largely unknown to one another, at least within wide limits. How did this come about? We can give one of two answers. The first is that we can understand human societies through general evolutionary principles that govern how social interactions between neighours will evolve in any kind of organism. We know that the distinctive features of the human body, such as our large brains, nearly hairless bodies and dexterous hands, have evolved through natural selection since the divergence of our lineage from our sister species, the chimpanzee, some five million years ago. Our social behaviour may have evolved in the same way, and by the same agency. The second point of view, however, is that our social behaviour, and the systems of ethics on which it is based, are uniquely human, and owe nothing to the processes that govern societies of ants or bacteria. Our bodies may have evolved, but our ethics requires another kind of explanation.
The fourth annual Lorne Trottier Public Science Symposium Apes or Angels: What is the Origin of Ethics? is about the clash between these two different views of human nature. We have invited the representatives of two disciplines to debate the issue, two disciplines which are superficially different but which nevertheless share the common bond of explaining how populations change through the conflicting demands of individuals who pursue their own selfish goals while remaining dependant on one another. We can look forward to a fascinating discussion between participants whose views may eventually lead us towards a synthetic interpretation of human nature.