Based on a speech by David Cameron on moral capitalism, this paper discusses moral and ethical implications of market systems. The free market system is looked at as a feature of capitalism and different ways and degrees of governmental intervention to regulate market practices in order to create economic well-being are outlined. A more detailed analysis of ethical and moral implications of an economy characterised by laissez-faire capitalism is provided. Additionally, different models and views on the social responsibility of companies are analysed, focussing especially on the work of Milton Friedman and Norman Bowie. Sainsbury''s is used as an example to examine CSR activities and the degree of its ethical and environmentally responsible behaviour by applying relevant ethical theories and sustainability models to date.