Environmental problems represent a challenge to economics. The neoclassical view of man as a rational consumer and of firms as profit-maximizing entities may be useful for some purposes but does not facilitate a debate about ethics and the social responsibility of business. In this essay 'political-economic man' is suggested as an alternative to 'economic man' and also organizations are seen as political entities. A view of markets in network terms is furthermore suggested as being complementary to the convential ideas of supply and demand. Finally, a 'holistic' idea of economics is advocated and used as a building stone for alternative approaches to societal decision-making. Together these elements comprise the skeleton of a microeconomics for ecological sustainability.