zygote is not A person

Shifting of the BoPMy opponent argues:"Your argument is backwards. You start with twins where everyone can agree they are human beings then you make the conclusion that where they came from must have already been a human being."Unfortunately, this is not what I am arguing. I am not arguing that a zygote is a person, rather I am refuting Pro's arguments that a zygote is not a person.I am under no obligation to show that a zygote is a person. Rather, I am under an obligation to disprove Pro's arguments.If the human person is immaterial...My opponent mistakes between the self and the body. While I agree that the self (if it is immaterial) cannot be split in half, the body can. I have never argued that the self can split apart into two selves.That being said, if the human person, or the "self" is immaterial, then there is no problem at all. The physical matter is what is splitting in half, not the "self."Perhaps the original person has ceased to exist, and two entirely new people have begun to exist! Perhaps the original person still exists in one half of the zygote, but a new person has begun to exist in the other half. These are valid possibilities. If my opponent accepts that the self is immaterial, then he must demonstrate that such things are impossible.If the human person is material...Now on the other hand, let's assume that the person really just is the physical matter of the zygote. But if this is the case, then it's not clear how there even is a problem.If the human person just is the physical matter, then my opponent's initial premise, that a person cannot be split in half, is obviously false. If the human person just is certain physical matter, then a human person most certainly can split into two new people. This is what happens in monozygotic twins.Argumentum ad ignoratiumMy opponent asks:"When an embryo splits in two what happened to the original person that now exists as two embryos/persons?"But such a question is irrellevant, and in fact assumes that the self is splitting in half, which is an unnecessary assumption, one I surely have not made. Even if we do not know what happens to the original person, it doesn't follow from this that the original zygote is not a person. This is simply an argument from ignorance; our lack of knowledge does not predicate that the zygote is not a person. (1)ConclusionIn conclusion, my opponent has not refuted my brain-splitting argument, merely passing it off as science fiction. I do, however, think it is a good example of what is at hand to demonstrate that we cannot infer the original zygote is not a person. I would also like to present this horned argument:P1: Either the "self" is immaterial, OR it is material.P2: IF the self is immaterial, THEN there are other options than the self splitting in half, and my opponents arguments fail.P3: IF the self is material, THEN the human self can, and does, split apart into two people, and my opponent's argument fails.C: Therefore, in either case, my opponent's argument fails.P1 is an application of the law of excluded middle. P2 and P3 have been argued for above. The argument is also logically valid. Thus, the conclusion follows necessarily.Sources:(1) http://www.fallacyfiles.org...