>>2650948From my understanding :
People live within a social system organized around a productive structure. This is the division infrastructure -> superstructure.
This social system determines their consciousness : their desires, needs, political rights etc. It shapes what they aspire or want. However, by doing so, it also creates the desire to modify or reshape the system.
The contradictions, really the opposing forces, are between the organization of the productive structures (i.e. how the workplace is organized), and the social consciousness that it produces. (i.e. what the proletariat desires).
This is a dialectical movement because the subject of the dialectic is neither purely in a contemplation of the world, and neither in a purely determination of the world (idealist).
To quote Engels in his anti-duhring :
>"Fundamental contradiction, whence arise all the contradictions in which our present-day society moves, and which modern industry brings to light."
>"A. Severance of the producer from the means of production. Condemnation of the worker to wage-labor for life. Antagonism between the proletariat and the bourgeoisie."
>"B. Growing predominance and increasing effectiveness of the laws governing the production of commodities. Unbridled competition. Contradiction between socialized organization in the individual factory and social anarchy in the production as a whole."
>"C. On the one hand, perfecting of machinery, made by competition compulsory for each individual manufacturer, and complemented by a constantly growing displacement of laborers. Industrial reserve-army. On the other hand, unlimited extension of production, also compulsory under competition, for every manufacturer. On both sides, unheard-of development of productive forces, excess of supply over demand, over-production and products — excess there, of laborers, without employment and without means of existence. But these two levers of production and of social well-being are unable to work together, because the capitalist form of production prevents the productive forces from working and the products from circulating, unless they are first turned into capital — which their very superabundance prevents. The contradiction has grown into an absurdity. The mode of production rises in rebellion against the form of exchange."
>"D. Partial recognition of the social character of the productive forces forced upon the capitalists themselves. Taking over of the great institutions for production and communication, first by joint-stock companies, later in by trusts, then by the State. The bourgeoisie demonstrated to be a superfluous class. All its social functions are now performed by salaried employees."
>https://www.marxists.org/archive/marx/works/1880/soc-utop/ch03.htm