Abstract
Family, as a basic cell of social functioning, is based among other presuppositions in the possibility of the attribution of legitimate fatherhood and maternity, ensuring the genealogical line, the inheritance of titles and the redistribution of wealth by inheritance. Thus, marriage, in a patriarchal society, is an indispensable institution in order to ensure the stated purpose. However, given the impossibility of proving paternity, only achieved in the second half of the twentieth century, through DNA tests, the problem of adultery of women, with the consequent possibility of procreation of illegitimate children, legitimized for marriage, for if they assume the putative father, poses problems in the application of commutative justice among sons and daughters, facing the principle of legal assurance in the case of inheritance of property and titles. We propose to discuss on the care to be taken in the management of the problem of adulterous children by the mother in order to protect the legitimate progeny and to maintain the basic foundations of the patriarchal regime. Our reflection is based on the Commentary of Francisco de Vitoria, O.P. on commutative justice and restitution.