Modernity is not meant to be mindlessly celebrated, but neither is it to be disdainfully dismissed. Its positive and negative qualities are for the most part aspects of the same process. This is why only a dialectical approach, one which grasps how contradiction is of its essence, can do it justice.

The class struggle is essentially a struggle over the surplus, and as such it is likely to continue as long as there is not a sufficiency for all. Class comes about whenever material production is so organised as to compel some individuals to transfer their surplus labour to others in order to survive. When there is little or no surplus, as in so-called primitive communism, everyone has to work, nobody can live off the toil of others, so there can be no classes. [...]

Social democracy is one bulwark between itself and disaster.

[...] the need for capitalism in order to have socialism. Driven by self-interest, ruthless competition and the need for ceaseless expansion, only capitalism is capable of developing the productive forces to the point where, under a different political dispensation, the surplus they generate can be used to furnish a sufficiency for all. To have socialism, you must first have capitalism. Or rather, you may not need to have capitalism, but somebody must. [...]

Marx's theory of history is not a "teleological" one. A teleological theory holds that each phase of history arises inexorably from what went before.