Pufendorf: On the Duty of Man and Citizen according to Natural Law

1. The issue of marriage is children; paternal power [patria potestas] has been established over them. It is the oldest as well as the most sacred form of authority [imperium]. It binds children to respect the Orders of parents and to acknowledge their preeminence over themselves.

2. Parents’ authority over children has its origin in two chief causes. The first is that the natural law itself, in commanding men to be sociable, imposes on parents a care for their children. To prevent negligence, nature has implanted in parents a most tender affection for them. Exercise of that care requires the power [potestas] to direct the children's actions for their own security, which they do not yet discern for themselves since they lack judgement.

Secondly, this authority rests also on the tacit consent of the child. One may rightly assume that if the infant had had the use of reason at the time of birth, and had been able to perceive that he could not survive without his parents’ care and the government implied by that care, he would gladly have agreed to it, and stipulated in return that they give him a good upbringing. In practice parents’ authority over children is established when they acknowledge them, feed them and undertake to shape them into good members of human society.

3. The mother contributes as much as the father to the generation of a child and so in a physical sense the offspring belongs equally to both of them. One must therefore inquire carefully which has the superior right to the child.

Here one must make a clear distinction. If the child was conceived outside of marriage, it will belong primarily to the mother. The reason is that the father can only be identified by the mother's testimony. Those, too, who live in natural liberty or above the civil laws may make an agreement that it is the mother's right, not the father's, that prevails.

But in states - and states have certainly been formed by men, not women - the right of the father will prevail, since a contract of marriage normally originates with the man and he becomes the head of the family.