Page:William Blackstone, Commentaries on the Laws of England (3rd ed, 1768, vol II).djvu/245

 Ch. 14. the grandfather and grandmother) one half of John's ancetors will not be the ancetors of his uncle: his patruus, or father's brother, derives not his decent from John's maternal ancetors; nor his avunculus, or mother's brother, from thoe in the paternal line. Here then the upply of proof is deficient, and by no means amounts to a certainty: and, the higher the common tock is removed, the more will even the probability decreae. But it mut be oberved, that (upon the ame principles of calculation) the half blood have always a much les chance to be decended from an unknown indefinite ancetor of the deceaed, than the whole blood in the ame degree. As, in the firt degree, the whole brother of John Stiles is ure to be decended from that unknown ancetor; his half brother has only an even chance, for half John's ancetors are not his. So, in the econd degree, John's uncle of the whole blood has an even chance; but the chances are three to one againt his uncle of the half blood, for three fourths of John's ancetors are not his. In like manner, in the third degree, the chances are only three to one againt John's great uncle of the whole blood, but they are even to one againt his great uncle of the half blood, for even eighths of John's ancetors have no connexion in blood with him. Therefore the much les probability of the half blood's decent from the firt purchaor, compared with that of the whole blood, in the everal degrees, has occaioned a general excluion of the half blood in all.

, while I thus illutrate the reaon of excluding the half blood in general, I mut be impartial enough to own, that, in ome intances, the practice is carried farther than the principle upon which it goes will warrant. Particularly, when a man has two ons by different venters, and the etate on his death decends from him to the eldet, who enters, and dies without iue: now the younger on cannot inherit this etate, becaue he is not of the whole blood to the lat proprietor. This, it mut be owned, carries a hardhip with it, even upon feodal principles: for the rule was introduced only to upply the proof of a decent from the firt purchaor; but here, as this etate notoriouly decended from Rh