utopian

of, relating to, or having the characteristics of a utopia; especially : having impossibly ideal conditions especially of social organization

proposing or advocating impractically ideal social and political schemes

impossibly ideal : visionary

one who believes in the perfectibility of human society

one who proposes or advocates utopian schemes

socialism based on a belief that social ownership of the means of production can be achieved by voluntary and peaceful surrender of their holdings by propertied groups