Facts and difficulties
A question is related to things that exist; and, therefore, an answer is related to the things which inspired the question.
This is a brief attempt to indicate the various things to which the principle, where the body lives, there the soul is, and where both are is the person, is an answering response.
If the loss of the soul is by definition the end of human life, then isn't the beginning of human life necessarily concomitant on the coming into existence of the soul?
For how can a human life come to an end by the departure of something, if that same something did not also constitute its first moment of life?
For how could there have been human life at all if there was not from the beginning of it that which, if it was absent, is the death of the body?
Therefore what is the nature of that beginning to human life such that death is the separation of things which belong together?
The life of the embryo is another human life806 to that of the child's parents and once this life has begun 'there is no particular part of the developmental process that is more important than another; all are part of a continuous process...'807.
In other words, it is precisely because from the beginning the child's development is continuous808, that this fact itself leads on to the conclusion that human life is seamless and, therefore, the mystery of its beginning is the time to consider the coming into existence of a soul and not at any subsequent stage of development.
Fertilization, however, is not the only point at which another life begins.
For identical twins are twins who come into existence, as twins, when a single embryo divides and each of them obtains the requisite physical integrity.
But the second twin does not receive its soul from the first twin.
For there was until this division only one body and therefore only one soul, as the soul is by definition the life of the body809, and so the second twin receives its soul from God on the coming into existence of its own body.
In other words, where the body lives, there the soul is, irrespective of how that body came into existence.
The body of the first twin is animated by a soul in such a way that not only can the normal process of cell division occur, but that the body of the second twin can come from the body of the first twin without the soul of the first twin animating the body of the second twin.
What makes this possible is indeed the precise characteristics of this early stage of the child's development.
For it is precisely at this early stage of development that the very nature of human growth which proceeds by way of cell division and duplication, is also the reason why it is possible for one human being to be, in a sense, begotten of another.
But one has to distinguish between the problems that our present knowledge presents the principle where the body lives, the soul is, where both are is the person, and the truth of the principle itself, such that it may be possible to establish the truth of a principle, on the basis of the available evidence, whether physical, philosophical and indeed theological, and at the same time recognise that certain elements of the question remain to be clarified.
It is obvious, for example, that until it is possible to say more definitively what the efficient810 and instrumental811 cause of a twin is, and whether it is operative at conception, or subsequently, or both, then to some extent it remains impossible to discuss, in relation to the fact of the ocurrence of a biological twin, what are the relevant and contributory factors.
However, what is already possible to say is that no sooner does the body of the twin exist, then so does the soul of the twin.
A related question arises, namely, if this principle is true, what can one predict on the basis of it?
For instance, if a living body must necessarily exist in order for there to be a soul to animate it, can one exclude the possibility that both identical twins exist at conception, precisely because there is only one body and therefore there can only be one soul animating it.
In other words, is it possible that a mechanism could be involved from conception, such as whether or not a second sperm attached itself to the egg after a first one had done, but that this "mechanism" didn't become operative until a certain point in the early development of the already existing child.
But it is possible too for another, and as yet unkown external factor to be involved, which may or may not require a preceding and predisposing cause.
In other words, if it can be stated unequivocally that the embryo first formed at conception is one embryo, then it can be said, also unequivocally, that the twin must necessarily come into existence at a later stage.
Thus the truth of the existing principle is verified, precisely in its power to inform the investigation, as distinct, even, from the point at which the results of the investigation confirm it.
Conversely, it could be argued, if this principle is true, where the body lives, there the soul is, then even if identical twins are simultaneously conceived at conception, then there will be the physical existence of these two at conception.
Now if the definition of what an embyro is is that it is a one cell body812 at this first stage, then it must follow that there cannot be, intrinsically, other than one human being in existence at that point.
Therefore, whatever the process by which the subsequent twin comes into existence, it must be at a time subsequent to when the first one did.
Another and related question is whether or not the first child dies and there comes into existence, at the moment of twinning, two different children to that of the first one.
For it to be said, however, a death has occurred, there must be a dead body.
But there is not a discarded body.
Therefore what has taken place has not involved a death, even the death of one embryo being consumed by the twins to which it gave rise.
For there is no stage at which it can be said that the twins come into existence by birth, as it were, and then went on to digest their "parent."
Thus, whatever the process by which the twin comes into existence, it is one which involves the continuation of the life of the first child.
Another unanswered question pertains to the possibility of an embryo dividing to the point of bringing into existence twins and then recombining813.
This question requires a factual base to determine, initially, just that: what are the facts. Nevertheless it is possible to assert that if the beginning of the union of the egg and the sperm is what conception is, then at least the following question would seem to require investigation: is there a similar act of beginning which begins the twinning, as begins the existence of the individual from the union of egg and sperm?
Further discussion of this point would require, I think, further information on this point; however, given that things have beginnings, it does not seem unreasonable to say the following: that where the body of an individual begins to live, there the soul is, and where both are there the person is - irrespective of whether the body begins to be and to live as a result of sexual or a-sexual reproduction814.
In conclusion of this question one can say that the bodily person of a twin comes into existence at the moment of the beginning of what constitutes another bodily existence to that of the first; and, secondly, while developmentally all sorts of things might occur, such as an incomplete separation of the two twins, what cannot occur without the death of one of them - once they have begun to be - is that one of them simply ceases to be.
In other words, whatever the phenomenon of what looks like the formation and then the recombination of twins - bearing in mind that one child can end up inside another one - determining whether or not twins have formed and then recombined is quite different to determining that 'cells' have separated and recombined.
For if it is the former then either a death has occurred, an extraordinary double conception or it was not a true 'twin'; and if the latter has occurred, then this is either a part of the normal process of development and its variations, or it is an abnormality of some description.
But, and this is in a way the point, if another 'twin' comes to be and then ceases to be, then whatever form that ceasing to be takes - which is a death - it must be possible to recognise that a dead body has either been in some as yet unknown way assimilated by the bodies around it or it remains in the body as dead and is 'born at the same time as the surviving twin.
Finally, what is evident from the existence of conjoined monozygotic twins - which are the result of the partial division and therefore incomplete separation of the one embryo815 - is that the complete physical separation of the twins is not a precondition for the coming into being of two people: of twins.
In other words, as I argued earlier, it is the beginning of what constitutes the reality of the existence of twins which constitutes the moment of the existence of both people being ontologically complete and thus each one of them being equally body and soul.
Therefore it is again obvious that the soul is made at the beginning of the becoming of a twin and that,if the physical separation does not complete what has begun, nevertheless two people exist from the moment of that beginning.
Similarly, as I've argued earlier, the crucial fact, from the point of view of answering the question when did I begin, is not when is that process complete - but when did it begin: conception, whether of an individual or of twins, is about the moment of beginning!
Thus, as I have said repeatedly with respect to this question, a deeper knowledge of embryology is necessary to answer this question in more detail.
A final question to which I want to turn is the following one: how are we to understand what constitutes the necessary and sufficient basis of the living body: the body, therefore, where the soul is and which, body and soul, the person is?
The same requirement applies to this, as indeed to all these technical questions, namely, that of an adequate data base to the discussion; however, at this point all I want to observe is the following: if a person has an extra digit on their hand this does not of itself constitute the case of unseparated twins.
Therefore, what constitutes the physical basis of the person?
Clearly the answer follows from observing what can be held in common by unseparated twins and what must be distinct if it is to be truly said that this is a case of twins who are incompletely separated.
But in general it can be said that the complete integrity of the completely separated body of the individual is the good to which nature tends because of the intention, inherent to it, of the Creator; and, if this does not occur, it would be a help to the people concerned to assist the development of this fact if it can be done in a humane way and with a humane result.
In conclusion, there is both a radical beginning of my life, which recapitulates the creation from nothing of the beginning of creation, and there is the incarnation of my soul on its coming into existence, such that it cannot be said to have been in existence before the union of egg and sperm, but rather comes into existence at the moment of that beginning we call conception - but which comes into existence as the 'form' of that body.
What, therefore, does it mean to say that the soul is the 'form' of the body?
Secondly, the absolute individuality of the soul is mirrored in the unique inheritance, as it were, of the body.
Thus, while traditional philosophy would have treated of the individuation of the soul by the body - whereby the "matter" of the body differentiates, as it were, the identity of the soul - it would seem that the phenomenon of genetically identical twins - twins which arise out of the early division of the embryo - indicate that the soul is also a factor in determining the identity of the person.
If the soul only determined life and not identity then identical twins would be identical persons.
For in both cases it is the same 'material' which individuates each soul.
Finally, considering the widely divergent views on the nature of the embryo, is a common knowledge of it possible?
Firstly, the existence of the human embryo is a fact presupposed by the differing perceptions of it.
For even the possibility of a public delusion concerning such a thing presupposes a thing that made the delusion possible, in that thought does require a thing to exist if it is going to be thought about, even if what is thought is mistaken, a deliberate misrepresentation of what in fact does exist, or, as in the case of true fiction, the thought is an imaginative development of what does in fact exist.
Therefore, while the difficulties of knowing what does exist seem to exceed the possibility of obtaining common knowledge of what does exist, nevertheless it is the common fact of a thing's existence which constitutes both the necessary presuppostion of a common knowledge of it and, therefore, furnishes of itself the necessary determinants of our knowledge of it.
On the one hand, then, it is in the very fact of the existence of things that there is to be found the rule of thought, as it were, in that thought, scientific thought particularly, is both a response to and an investigation of what exists, where what exists also, in virtue of its existence, manifests its existence in activity; and it is this activity of the existent thing, in this case the embryo, which continually calls, as it were, for the right formulation of what this extramental thing is816.
On the other hand, precisely because we are different to oneanother and that we will see things through our selves, a fact each of us has in common, does not of itself make common knowledge impossible.
For if it did then not only would our differences have to be fundamental but they would also have to constitute a profoundly unconquerable, mutual unintelligibility: an incommunicability so profound that it is inconceivable that we should know anything; indeed, an incommunicability commensurate only with our non-existence.
But as we cannot both not exist and know that, then existence implies its communicability.
In other words, intelligibility follows on, is commensurate with, the fact of our existence817.