The discourse about solidarity in European social democracy developed in societies that shared many common characteristics and that went through the processes of industrialisation and urbanisation. Not only was the working class more or less excluded from governmental institutions and political influence, it was confronted with dangerous working conditions and miserable housing conditions, and a bourgeoisie that defended its privileges and resisted change. It had to relate to farmers, smallholders and an urban petty bourgeoisie that identified neither with the working class nor with the bourgeoisie. The growing labour movement needed an ideology that united the class, and this is what Marxism offered. Within this common frame, national characteristics varied and influenced both the general ideology of the labour movement parties and the extent and the kind of solidarity discourses that were developed.

This chapter describes the process that made social democratic parties adopt an idea of solidarity; how different equivalent terms for this idea were replaced with solidarity and how this concept was transformed. It discusses national characteristics and throws light on why social democracy in some countries introduced the new and modern concept and developed a full discourse on solidarity earlier than others, and the contexts in which socialist and social democratic parties adopted a modern and broad concept of solidarity.