Mater semper certa est
In Roman law, mater semper certa est (from Latin: "the mother is always certain") is a legal principle which has the power of praesumptio iuris et de iure ("presumption of law and by law"), meaning that no counter-evidence can be made against this principle. It provides that the mother of the child is conclusively established, from the moment of birth, by the mother's role in the birth.