Our intention is to demonstrate how Marx's integrated understanding of capitalism in general, which follows from his theory of the determination of value by labour-time, helps us to understand the particular question of knowledge-based production. We do not believe that Marx's analysis of capitalism is narrowly historically specific to any 'stage' of capitalism, but that it applies to capitalism in general, so the growth of knowledge-based production does not require us to 'modify' Marx (as in, for example Hardt and Negri 2000). Furthermore, we contend that Marx cannot be meaningfully or adequately applied a-al-carte. Marx's theory of value implies a certain definition of what is 'productive' and 'unproductive' labour. Consequently if we specify, for a particular purpose, a different definition of 'productive' and 'unproductive' labour (like, for example Harvie 2006), we lose any coherent link to Marx's theory of value and the inherent tendencies within capitalism that Marx identifies, through employing his theory of value i.e. we lose Marx's bigger picture. However, since Sweezy (1942) popularised Bortkiewicz's 'proof of Marx's 'errors', Marxist economists have accepted that Marx's theory of value is internally inconsistent anyway, and have consequently 'corrected' Marx a-al-carte, preserving only differing sub-sets (according to their chosen manner of correction) of Marx's original conclusions. For the totality of Marx's vision of capitalism to be taken seriously, Marx must be rescued from allegations of internal inconsistency. The Temporal Single System Interpretation (TSSI) of Marx precisely sets out to achieve this goal. The TSSI explains that if we interpret Marx as having a sequential and non-dualistic method (see below), then Marx is, and always has been, internally consistent, bringing the totality of Marx's vision back into business. We can thus apply an internally consistent holistic Marx to the question of knowledge-based production. Our first section further explores the question of the internal consistency of Marx's theory of value. Section two considers how Marx's conception of capitalism as the unity of a valorization process and a labour process shapes our conception of what is productive (and productive of what). Section three explores how Marx's definition of productive and unproductive labour is relevant to knowledge-based production. Section four focuses on how to understand research and development, a knowledge intensive activity, in the context of Marx's theory of value. Section five tries to assess questions of training/skills in our knowledge-based society, informed by Marx's concept of simple and more complex labour-power. Finally we conclude, in the context of what George Lucas considers to be the value of 49 seconds of film/knowledge-based production.