research of " as an argument with a critical approach to new ways of parentage's proof "

one of the known rules of jurisprudence is a rule called firash that derived from the hadith of the priphet, that means child is for his father and stone is for adulterous. as a result of this rule, a child born to woman- by supposing all firash conditions-is belong to the man who has an offical life with that woman not adulterous or others. iranian civil law to comply with this rule,codify the rule by this name in law. in past, this rule specified the child's prentage. nowadays, new ways of proof the parentage such as blood test and dna are emerged and experts say some of these ways have about 100% finality. in this essay, we try to criticize scientific and moral reasons of people who agree with new ways of proof the parentage. by this way we want to prove the reasons of people who believe that firash is a beyond time and place rule that can still be useful in determining these kinds of children's parentages.