Marxists killed playful utopianism, thus saving the unity of the [Social Democratic] Party and ‘scientific rigour’, but also paralysing the resolve to think up new forms. The doctrine of historical necessity became quietism for many; what Marx said about active engagement in reconstruction was forgotten. As if conscious work on the order of society with a specific goal would be opposed to the realisation that what is willed as well as the willing are necessary for development!

— Economic Writings by Otto Neurath, Thomas E. Uebel, R. S. Cohen (Page 345)