So far, studies of Swedish 20th-century social policy have emphasized the differences between the voluntary aid common around 1900 and the solidarity of welfare policy at mid-century. Means tests have been described as central instruments in the voluntary social work, while the welfare state was built on general principles of care. The question is, however, if the differences between the earlier and later forms of social policy can be characterized in such simple terms. A comparison has been made of departure points found in the social policies of the two periods. The results confirm that a significantly new way of thinking had taken shape in the years around the Second World War, but the study also shows that that the ideas concerning the welfare state contain threads that can be traced back to the scientific philanthropy of a few years earlier. The idea of social engineering was nothing new, and the idea that rights could be exchanged for duties had still not been deserted in the 1940s. In conclusion it can be said that the welfare state and the welfare politics of solidarity in several respects were built upon the principles of care that were formulated in about 1900.