Abstract We consider whether public corporations can be ethical, using the notion of corporate social responsibility (CSR). We distinguish between ‘weak’ CSR (where corporate profitability is enhanced by pursuing social and environmental objectives) and ‘strong’ CSR (where it is not) and consider four possible positions in relation to strong CSR. First, CSR is unnecessary – good ethics is synonymous with good business. Second, CSR is unethical as the government is responsible for intervention in markets. Third, CSR is ethical and is being implemented by corporations. We find none of these positions convincing and argue a fourth position – CSR is ethical but impossible for corporations to implement due to competitive markets and the legal requirements of the corporate form. We conclude that public corporations are best considered amoral entities. In order to alleviate the inevitable negative social and environmental outcomes arising from corporate activities, we suggest strength