eastern orthodox church and other eastern churches i am not a writer or an editor so i am not sure how to approach the correction of the page nor am i a genealogist or a theologian so i'm not really schooled in the subject matter so i could be wrong about this in the article under the heading of eastern orthodox church and other eastern churches it says however in the eastern orthodox church marriages of affinity that produce children who are closer genetic relatives than legal are also not permitted unless the genetic relationship does allow marriage between those children for example two siblings may not marry two other siblings because legally their children will be cousins but genetically they'll be half siblings on the other hand two siblings may marry two cousins although i am not sure what the laws are in the eoc regarding marriage of first cousins i believe the example given is in error half siblings are children who share one parent either the father or the mother i believe that their children would in fact be cousins in two lines however according to the wikipedia page on siblings two of the siblings in the scenario were identical twins this would in fact make their children genetically equivalent to half siblings as well as cousins as for the second example of two siblings marrying two cousins their children would be first cousins in one line and second cousins in the other line again i have never formally studied genealogy and have no references so don't take this as an affront but i think i am correct thank you