Rosa Luxemburg wrote that 'Freedom is always... freedom for the one who thinks differently'. She was a partisan of the idea of democratic pluralism within the socialist movement. Her ideas on this topic also had their limitations, but hers was a humane and powerful voice, within the Marxist tradition, for taking the values of freedom and democracy seriously.
I draw your attention to this appeal from the editors for support in publishing a complete edition of Luxemburg's works. The appeal is for help in funding the venture.