While completing the translation, Danielson initiated a correspondence with Karl Marx and Friedrich Engels, which continued for the rest of their lives.

But whereas Vorontsov claimed that the development of industrial capitalism in Russia was impossible for lack of markets and Mikhailovsky thought that it was possible but undesirable and preventable.

However, in the 1890s, Plekhanov, Lenin and their associates argued that capitalism in Russia must follow essentially the same course as capitalist development in Western Europe.

Danielson argued that capitalism was essentially dispensable for further economic development, and that industrialisation could continue on the basis of a socialist economy.

In the early 1900s, Danielson was briefly involved with the Russian Socialist-Revolutionary Party, but he did not play a very active role in it, and he withdrew after the "Azef affair" of 1908.

(Yevno Azef was a prominent leader of the PSR and the chief of its terrorist organisation; in 1908 he was unmasked as a double agent for the Okhrana, the secret police.)