In 1803, Claude Henri de Rouvroy de Saint-Simon creates a new kind of religion that worships science and propose as main "prophet", Isaac Newton. This "religion" is founded on philanthropic basis, yet it did establish the roots of what we nowadays know as technocracy. Science was supposed to unify human beings; that is how Charles Fourier designed his Phalanstere in the early 1800's thinking that a rational architecture could achieve a utopian communitarism. He was followed by Jean-Baptiste Godin and his Familistere built in 1858.
However, those designs were over-controlled - technology has to be precise - and were revealing the deep condescending aspect of philanthropy established by the high educated social class on the lower working class. Both Phalanstere and Familistere's architecture are built in a very introverted way, supposed to maintain the community's spirit, however the apparatuses of surveillance they therefore imply make them organized pretty much like prisons are.
Moreover, in its various schemes, Saint-Simonianism considers the human as a decontextualized being only influenced by a kind of Rousseau-ist prevailing nature. Such considerations can establish theoretical and probably valuable reflections on society, nevertheless their application can only lead to failure or worst totalitarianism.
Marx and Engels, on the other hand, denied any kind of human nature and were strictly circumstantialists. They believed that each human was the product of the society he lived in and that building new social schemes could not be achieve in a vacuum but rather by creating on the first place a resistance towards the establishment. This way, rather than designing what may be good for people, they were putting the latter in front of their responsibilities preventing them from any transcendental control that was existing in the case of XIXth century philanthropic projects.
In the same spirit and approximately at the same time, Pierre-Joseph Proudhon was also encouraging this humanist emancipation by claiming that "labor destroys property" and that "property is thief", prophesying the revolutions of 1871 (France) and 1917 (Russia).