It would not suit modern Europeans to have, on a mass scale, the kind of flamboyant attachment to ideology found in contemporary revivalisms. God is dead; there is no innate universal moral sense; and Plato's virtuous republic is only a dream. What, then, is the basis of law and morals? Onora O'Neill suggests we replace the old metaphysical certainties with a new secular "constructive account of practical reasoning". Moral principles are, for her, not merely personal choices parading as universally applicable policies. No; we can reasonably recommend our moral standards to our opponents.
The author insists that the rules of practical reason should rely on no controversial metaphysical assumptions. Intelligible, capable of being followed by all, such rules are neither causes that fully determine conduct nor platitudes that completely fail to guide it. Global in scope but not uniform, these are flexible guidelines with room for exceptions, for judgement and creative variation.
O'Neill identifies some empirical beliefs or rules whose denial or implementation involves self-contradiction. For example, "Everyone should severely injure everyone else" cannot be universally implemented.
Necessarily, it is exclusive. Again, empirical assumptions that enable ordinary activity cannot then consistently be denied for specifically moral activity. Thus, fascist dehumanisation of victims is incoherent: a Nazi pretends to see Jews as subhuman yet uses instruments of torture designed precisely for torturing recognisable human beings.
O'Neill's proposed rules seem truistic and disappointingly meagre as a foundation for ethics. But she is a Kantian: she begins with humanly available materials and builds. No metaphysics here. We moderns cannot build, in Kant's words, "any tower that reaches the heavens". She criticises John Rawls's famous theory of justice for its hidden liberal metaphysical presuppositions about the self, reason, and the psychology of motivation.
But what makes a theory of justice "uncontroversial"? And why does it matter? Uncontroversial theories could be false and controversial ones could be true. Besides, is a philosophical view uncontroversial as long as the only people who take exception to it are infants, lunatics, and rival philosophers?
Take the author's claim that we do not need a "metaphysically conclusive" account of moral personhood. "Who counts as a moral agent?" is a tricky question. Excluded at various times were foreigners, infidels, women, slaves, and children. Today, many wonder about the status of animals, robots and the foetus. O'Neill knows that a convincing theoretical account of moral personhood is unavailable but thinks that a "practically adequate but theoretically incomplete" one would suffice. But suppose a rival thinker dismisses a proposed account as theoretically contentious and practically defective. Surely, the most intractable disputes involve assumptions for which we can attain neither theoretical nor practical unanimity of opinion. Hence, our modern anguish over abortion.
The obligations of justice, writes O'Neill, are rooted in a principled rejection of direct and indirect injury to other people and the environment. And we must supplement justice with private virtue because not all our vulnerability to harm is of the type against which just institutions can legislate. We are not, she continues, fully rational or self-sufficient.
Hence the need for love, sympathy and solidarity and the environmental virtues of preservation and conservation for later generations. The rejection of avoidable direct and indirect indifference to and neglect of others and the common environment becomes the practical basis of the virtues.
But the principle that no one should severely injure others is unexceptionable only on the controversial assumption that ethical concerns should override aesthetic ones. An existentialist could argue that constructive violence sometimes inspires great art, that artists should be allowed to injure others or themselves. Admittedly, it is illegal for a painter to torture children to paint well. But is that not because, as Salvador Dali probably thought, our western idolatry of art is still imperfect?
O'Neill correctly notes that many ethical schemes cannot countenance supererogatory virtue - justice is never supererogatory - because they concede no moral category beyond duty. But while her account allows for such heroic or saintly virtue, it cannot accommodate moral decisions where whatever one does is, by definition, wrong, where the categories of virtue and vice are irrelevant. The word tragedy never occurs in this book.
In her philosophically precise prose, O'Neill makes many nice distinctions but rarely uses examples from real life and literature. The distinctions therefore look like academic sophistications. By contrast, the followers of Wittgenstein, whom she rightly criticises for their philosophical errors, do write in a way that makes moral philosophy relevant to our human dilemmas.
There is no question whose books Plato would have preferred to read.
Shabbir Akhtar is writing a biography of St Paul.
Towards Justice and Virtue
Author - Onora O'Neill
ISBN - 0 521 48095 7 and 48559 2
Publisher - Cambridge University Press
Price - £35.00 and £12.95
Pages - 230