Ius sanguinis is a social policy

Social policy

Social policy primarily refers to guidelines, principles, legislation and activities that affect the living conditions conducive to human welfare. Thus, social policy is that part of public policy that has to do with social issues...

 by which citizenship

Citizenship

Citizenship is the state of being a citizen of a particular social, political, national, or human resource community. Citizenship status, under social contract theory, carries with it both rights and responsibilities...

 is not determined by place of birth, but by having a parent(s) who are citizens of the nation. It contrasts with ius soli (Latin for "right of soil").

At the end of the 19th century, the French-German debate on nationality saw Ernest Renan

Ernest Renan

Ernest Renan was a French expert of Middle East ancient languages and civilizations, philosopher and writer, devoted to his native province of Brittany...

 oppose the German conception of an "objective nationality", based on blood, race or even, as in Fichte's case, language

Language

Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

.