The article shows the development of the status of an alien beginning from the ambiguous attitude to the stranger in antique Greece, where the stranger was both seen as a guest and as a potential enemy. This ambiguity changed in the middle ages with the beginning of biologically argumented racial antisemitism in Spain. The law of the ‘limpieza di sangre’, the ‘purity of blood introduced for the first time in history a biological argument to stigmatize a certain group. Biologically argued racism held out to be the cornerstone of discrimination in colonialism, while the idea of nationalism was constructing the stranger within a territory as a member of a minority. After World War Two both the ideas of biological distinctiveness and nationalism were, discredited in the sphere, of discourse. The alien nowadays is an alien by law, a person not sharing the same possibilities to participate in political action and on the labour market. Only a discussion of the implicit nationalism of the concept of the welfare state can open a way out of the discrimination of the alien by law.
