Children cannot survive on their own. They need others to feed them, to protect them, to care for them, to socialise them, to prepare them for life in society, and to represent their interests in (potential) conflicts. The satisfaction of children’s manifold needs is typically the work of many individuals and societal institutions, and many different combinations of individual and collective responsibility for children are thinkable, and have indeed been tried in the course of history. Nevertheless, all societies of which I know have rules designating specific individuals who bear the main responsibility for taking care of children, and who have the authority to take decisions for children. We call these specific individuals ‘parents’.

The question then arises on which grounds the said individuals are selected. The rules on the designation of parental status in contemporary family laws are quite complex, and take account of many particular interests. Nevertheless, the first and predominant legal criterion for the designation of parents is the biological tie. As a rule, a child’s parents are the woman who has given birth to them and the man who has fathered them. Most legal scholars appear to consider these basic rules as more or less self-evident, as do most other people. But are they? A look at history tells us that the rules can be quite different from what they are today, and that it is only recently that biological ties have become predominant. This observation alone should make us question the self-evident character of contemporary rules.

I will proceed in two steps. The first point I have to demonstrate is that, in contemporary laws, parental status is indeed derived from biological ties. It will be easiest to do this by contrasting present-day rules with their predecessors. This will have the side effect of denaturalising contemporary rules, for nobody could claim that rules are obvious, self-evident or natural if they can be shown to have been subject to fundamental change over the last century, or even in recent decades. The second step will then be to look for justifications of the present-day rules.