General notions of production found outside the borders of political economy are extremely vague. Any activity that results in a positive outcome at all is , to a certain extent, productive. Within the framework of political economy, however, this concept is given a precise and non-arbitrary content. To produce is to bestow a certain amount of human labour on an ensemble of products in order to produce another ensemble of products. While the conditions in which products takes place may prove to be more or less favourable, this does not alter the very nature of the act. (Dumenil and Levy)

The consequence which follow from this analysis are significant. Amoung other things we can see that although human labour is productive, not all human labour is productive. Further a machine does not produce, for it is only one element of the set of products on which labour is applied. It is a component which survives the process of production, older and more used. Land and the biosphere itself does not produce itself but rather determines the conditions of production. Only with human intervention does a plant become a product.

This is not as it might appear an arbitrary distinction because it is necessary to analyse a specific phenomenon. Boundaries and limits are necessary with discourses like this so that in this case when political economy views production and ultimately consumption in this sense it does so because to extend the concepts would be to weaken the sense of the analysis.