presumption of legitimacy A child born during lawful wedlock is presumed to be legitimate. The presumption may be rebutted only by strong preponderance of evidence, but even weak evidence against legitimacy must prevail if there is not other evidence to counterbalance it . Any presumption of law as to the legitimacy of any person may in civil proceedings be rebutted by evidence which shows that it is more probable than not that that person is illegitimate or legitimate, as the case may be, and it shall not be necessary to prove that fact beyond reasonable doubt in order to rebut the presumption.