The article starts from the proposition that present divisions in the subject of economics, its practice and teaching, are due to the existence of fundamental irreconcilable differences, which can be characterised as alternative theories of value. Three such theories are briefly outlined; the subjective preference theory which starts from the proposition of individual utility maximisation and logically derives monetarist policy; cost of production theory which sees the complex technical interrelationships of industrial society as demanding active, detailed state intervention to regulate and coordinate; and abstract labour theory, with the tensions of class struggle finding their reflection in political activity and threatening the position of the commodity relationship as the basis of social existence under capitalism. The authors suggest that teaching economics principles would be better organised if these different theories of value were taught sequentially as internally consistent rival schools of thought.