References to identity in this debate come from objectors to this argument, who apply the argument from fission to a real life version of it, namely, twinning. An embryo might split any time generally before the two-week point in fetal development, and those two embryos could develop into fully formed infant twins. The question for the advocate of the above argument to consider is, in such a case, what happens to the original human being, the embryo we will call Adam? There are only three possib