What role should morality or ethics play in economic interactions on markets? Much previous thinking on business ethics is unhelpful since it is polarised between two implausible extremes. Some neoclassical economists such as Milton Friedman believe ethics has no place in the market. We call this idea ‘economism’ and argue that it sits oddly with general intuitions about the importance of morality. On the other side are those philosophers who hold that traditional ethical theories, such as deontology or virtue ethics, can be applied just as readily in the business realm as they can in all other areas of social life. We call this idea ‘moralism’ and argue that it is unrealistic and unhelpful for typical interactions on competitive markets. We finally outline a more plausible alternative which is more balanced in this regard – the moral leeway approach to business ethics. Moral leeway accepts that the market is, in one sense, exceptional, in that actions which would be sanctioned in other spheres of life are accepted. But such leeway is only permissible in the context of a strong social network that ameliorates the sharp edges of the market.