General intellect, according to Karl Marx in his Grundrisse, became a crucial force of production. It is a combination of technological expertise and social intellect, or general social knowledge (increasing importance of machinery in social organization). The "general intellect" passage in the 'Fragment on machines' section of Grundrisse, says that, while the development of machinery led to the oppression of workers under capitalism, it also offers a prospect for future liberation.
Nature builds no machines, no locomotives, railways, electric telegraphs, self-acting mules etc. These are products of human industry; natural material transformed into organs of the human will over nature, or of human participation in nature. They are organs of the human brain, created by the human hand; the power of knowledge, objectified. The development of fixed capital indicates to what degree general social knowledge has become a direct force of production, and to what degree, hence, the conditions of the process of social life itself have come under the control of the general intellect and been transformed in accordance with it; to what degree the powers of social production have been produced, not only in the form of knowledge, but also as immediate organs of social practice, of the real life process.
According to Marx, the development of the general intellect manifests in a capitalist society, in the control of the social life process. In other words, with the idea of the general intellect, Marx designates a radical change of the subsumption of labour to capital and indicates a third stage of the division of labour. The concept has several interpretations. For instance, Paolo Virno maintained that "general intellect" does not only thrive in communism, as Marx originally thought, since it also characterized other economic systems such as the post-Fordist capitalism. Here, it is suggested that Marx underestimated the extent to which the general intellect would develop within capitalism, particularly in the modern period where the concept is said to have been realised but with no revolutionary or even conflictual repercussions.
According to Matteo Pasquinelli, Marx took the expression 'general intellect' from William Thompson's book An Inquiry Into the Principles of the Distribution of Wealth (1824) which is probably the first book ever written on mental labour. According to Pasquinelli the concept disappears in the transition between the Grundrisse and Capital as it is replaced by the notion of collective worker or Gesamtarbeiter.