Question about beginning of human life an identical twins

[catholictiger]

No that is the exact opposite of what I said. Please re-read it,.

Where do you get that I said there are two individuals at conception??

At conception, there is one body, one soul, thus one person.

The zygote splits, the biological offshoot of the split is ensouled with a second soul. Thus there are two bodies, two souls, ergo two persons.

The second person is ensouled after conception.

Look at the example of Adam and Eve. Adam was a human person. Elements of him (in his case, a rib) and formed and ensouled into a new person, Eve.

It would be a logical falicy, and a false reading of Scripture to make a claim that Adam was two individuals prior to the removal of his rib. Likewise, it would be false to state that there are two individuals at conception.

sorry I misread it that makes sense now.

 

[catholictiger]

can anyone explain why the second twin isn’t beginning at conception is an exception to the rule of life begins at conception, or a new person begins at conception. Because I’m sure some of the pro choicers would agree with you to a point but then say how can you say life begins at conception taking into consideration these facts.

 

[cpayne]

Since Thomistic philosophy was mentioned in the OP, I’d just point out that Thomas has a fairly simple response to this question: any being is multiplied into more beings as the number of bodies is multiplied. For example, a flatworm cut in half is then two living flatworms, genetically identical, but distinct from each other.

A single human zygote is one human being; if it twins, it becomes two human beings. That in itself is enough to warrant our protection, even without the ensoulment discussions.

Dear Tingo: You wrote, “Egg and sperm can create a genetically distinct tissue which is not a human life I.e. has no characteristics of a human just tissue.”

I think perhaps you are referring to things such as hydatidiform moles? In that case, you are right on the facts, but I don’t think there is any moral significance in those facts. As Francis Beckwith puts it, every human life begins at conception, but not every conception is a human life.

 

[cpayne]

Dear ThinkingSapien: You wrote, “Personhood status is not an assertion of whether or not it is human, but is something related to law and a philosophy of rights.”

I agree that many do think this way nowadays, but this makes personhood so philosophically arbitrary, don’t you think? Everyone seems to have his or her own list of functions and abilities after the possession of which the human “being” becomes a human “person.”

It seems better to go with the older definition from Boethius, that a person is an “individual substance of rational nature.” This puts the focus on the “nature” of something, rather than on some arbitrary list of abilities. Scientifically, the nature of the human zygote is that of a being of rational nature (homo sapiens), which makes the zygote a human person and deserving of rights.

 

[rossum]

this is a very simple question, but in the devlopment of identical twins the zygote will split in two and create two identical Human Persons, we see it all the time in society, twins who look exactly alike had this happen to them. The Church teaches and I think good solid thomistic philosophy holds that life begins at conception. But here is the question in the case of identical twins at conception you have one person but when the zygote splits you have a new human person. How can we claim philosophically that life beings at Conception taking into consideration this fact. Is this an exception to the rule or should we reconsider our view on when life begins.

Just to complicate things still further, there is also the question of the reverse process, human chimeras. What would be two fraternal siblings from two separate conceptions merge at a very early stage and form a single individual with a mosaic of two different sets of genes. See Sons I gave birth to are ‘unrelated’ to me for an example.

rossum

 

[Brendan]

I don’t think you will get any disagreements on the egg, sperm, and zygote being composed of living cells. The disagreement comes when some one makes an assertion on whether or not it has personhood status. Personhood status is not an assertion of whether or not it is human, but is something related to law and a philosophy of rights.

Why, if one does not recognize a metaphysical reality, then there remains only the scientific definition of being of species homo sapiens, correct?

if one recognizes a philosophy of rights, but then defines those rights as belonging to a person, but then defines a person as one having those rights it is a circular argument and illogical.

Personhood, must therefore have a definition distinct from any concept of rights.

To an athiest, one who denies metaphysical reality, the only concept then is either the scienctific defintion of species, or via human law. If human law, then the athiest must attest that slaves were not people, and only gained personhood status when there were granted freedom. Ergo, slavery could never be a violation of personal rights.

A thiest, on the other hand, or one who recognizes metaphysical reality, can rely on a personhood defintion that incorporates the metaphysical reality ( such as the Catholic defintion of Personhood being a Moral Actor, Morality being a metaphyscial reality)

But there is the question of “Human Rights” , in common paralance, the concept of Human Rights would indicate that they belong to humans, which lends itself to the scientific defintion of homo sapiens.

Would you claim that there are no such things as 'human rights", but only ‘personhood rights’

If so, what then is your defintion of person? Is it legal, metaphysical or biological.

 

[ThinkingSapien]

I agree that many do think this way nowadays, but this makes personhood so philosophically arbitrary, don’t you think?

I don’t think it’s arbitrary. Historically it seems to have dependent on who was “in control” and what empathy that the person or people that were in control have for those that are not. Though this also means that historically not all humans have been granted personhood . There is still ongoing discussion on this.

Why, if one does not recognize a metaphysical reality, then there remains only the scientific definition of being of species homo sapiens, correct?

Well, no. I think you might have overlooked where I made it known that this isn’t about determining whether or not an entity is human. There’s been discussion of granting personhood status to certain apes, whales, and other non-human animals. One that has personhood has protection under the law. I should also make clear that I am speaking in a legal context.

if one recognizes a philosophy of rights, but then defines those rights as belonging to a person, but then defines a person as one having those rights it is a circular argument and illogical.

I think I’ve been misunderstood and I hope that my response has helped in clearing up any misunderstanding. I think the above is based on a misunderstanding (and thus is non applicable). If you think that it is applicable please let me know.

To an athiest, one who denies metaphysical reality, the only concept then is either the scienctific defintion of species, or via human law.

Once again, this not on the question on whether or not one is human.

If human law, then the athiest must attest that slaves were not people, and only gained personhood status when there were granted freedom. Ergo, slavery could never be a violation of personal rights.

I think here your intended meaning is do the slaves have natural rights. That’s another question.

Staying in the legal context the question of if slaves gained personhood after the signing of the Emancipation Proclamation is equivalent to the question on if slaves gained the full protection of the law after the signing of the Emancipation Proclamation. Note that this question is in no way dependent on one’s religious disposition. Regardless of whether or not some one is declared to have a certain natural right without personhood the law might not provide protections for that person’s exercise of that natural right.

But there is the question of “Human Rights” , in common paralance, the concept of Human Rights would indicate that they belong to humans, which lends itself to the scientific defintion of homo sapiens.

That’s fine. But I spoke of “personhood.” While the concepts are related, they are not quite the same.

Would you claim that there are no such things as 'human rights"

Nope. I’ve neither declared nor have implied that. . I occasionally read through the Universal Declaration of Human Rights. I like the document’s intent.

, but only ‘personhood rights’

I’m not quite sure what you are asking here.

If so, what then is your defintion of person? Is it legal, metaphysical or biological.

The meaning of words depends on the context in which they are used. I mentioned above that I am talking about “personhood” in a legal context; a label used for the status of having the full protection of the law.

 

[Brendan]

I

That’s fine. But I spoke of “personhood.” While the concepts are related, they are not quite the same.

Nope. I’ve neither declared nor have implied that. . I occasionally read through the Universal Declaration of Human Rights. I like the document’s intent.

Ok, so you accept that there are human rights, which, by defintion, would apply to all humans.

Since you, as Catholcs do, recognize that there is a difference between human and person, would you recognize that human rights belong to all humans (which can be scientifically defined).

Ok, fair enough.

 

[cpayne]

Dear Brendan: You wrote, “Since you, as Catholcs do, recognize that there is a difference between human and person,…”

I do not think this is accurate regarding Catholic thought, specifically Thomistic thought. Any human being is a person: an individual substance of rational nature. If one bases personhood on functional abilities, as ThinkingSapien seems to want to do, then one can treat them differently legally. A human would not be a “person,” in that view. But that is not the Catholic view (nor is it scientifically defensible). It’s just another way to mistreat humans we don’t want around.

(later editing) I just re-read your post, and actually I think we are in agreement. I’m just quibbling with the way something was expressed.

 

[Brendan]

Dear Brendan: You wrote, “Since you, as Catholcs do, recognize that there is a difference between human and person,…”

I do not think this is accurate regarding Catholic thought, specifically Thomistic thought. Any human being is a person: an individual substance of rational nature. If one bases personhood on functional abilities, as ThinkingSapien seems to want to do, then one can treat them differently legally. A human would not be a “person,” in that view. But that is not the Catholic view (nor is it scientifically defensible). It’s just another way to mistreat humans we don’t want around.

(later editing) I just re-read your post, and actually I think we are in agreement. I’m just quibbling with the way something was expressed.

My point in expressing Catholic teaching was to note that the Catholic understanding of ‘person’ is that of a Moral Actor, one with the capability\potentiality to do moral acts. As we well know the Trinity is composed of three Divine PERSONS in one Godhead. So it is clear that every human is a person, there exists persons that are not human.

 

[Aelred_Minor]

so you would say its an exception to the rule of life begins at conception instead of a flaw in the argument?

some pro-choicers refer to this to try to punch a hole in the logic of the Catholic Church.

Sorry, I just revisited this thread. Yes, technically this would be an example of a human life begining in a way other than ordinary conception (with gametes fusing). Artificial cloning would be another exception. Ultimately, human life begins whenever the life of the human being really begins. When a conception occurs, that is the begining of the life of a human bening, but there are other ways human life sometimes begins.

 

[Aelred_Minor]

The Church has taken the position that life begins at conception. However, the Church has not taken an official position on when ensoulment occurs. It is very possible ensoulment occurs some time after conception.

One does not need a formal Church teaching on the subject to know from reason that a living human being has a soul.

 

[rossum]

One does not need a formal Church teaching on the subject to know from reason that a living human being has a soul.

Buddhists would disagree.

rossum

 

[Aelred_Minor]

Buddhists would disagree.

rossum

Well, if I’m not mistaken Buddhists would not agree that any truth can be reached through faith or through reason, at least as Westerners classically use the terms “truth”, “faith”, and “reason.”

 

[ValPal]

One does not need a formal Church teaching on the subject to know from reason that a living human being has a soul.

Maybe you can explain the procedure of how a soul splits in two/three/etc., which is exactly must occur if ensoulment occurs at conception and identical twins/triplets/etc. occur.

 

[rossum]

Well, if I’m not mistaken Buddhists would not agree that any truth can be reached through faith or through reason, at least as Westerners classically use the terms “truth”, “faith”, and “reason.”

Faith is only a start. At the beginning of the path you need to have faith that you are on the correct path, and not on the wrong path. As you progress along the path, faith is replaced by knowledge. You know that the path reaches a certain point because you yourself have reached that point. Faith about that aspect of the path is no longer required.

Faith is always provisional, it is eventually replaced by knowledge.

Reasoning is very definitely used, try reading some Nagarjuna for example. However, Buddhist reasoning starts from different premises than are common in Western philosophy, much of which is based on Greek thought. Nagarjuna’s philosophy is based on Indian, not Greek, philosophy.

Truth is whatever corresponds to reality:

Mind precedes all conditions,
mind is their chief, they are mind-made.
If you speak or act with an evil mind then suffering will follow you,
as the wheel follows the draught ox.

Mind precedes all conditions,
mind is their chief, they are mind-made.
If you speak or act with a pure mind then happiness will follow you,
as a shadow that never leaves.

Dhammapada 1:1-2

rossum

 

[mharren]

Wow, this is a really interesting question. I love it!

In the study of embryology we don’t actually completely understand how or when a monozygotic twinning occurs, but I was always taught that it was suspected to occur when the embryo reached the stage of being a Blastocyst (And inner cell mass [these cells give rise to the embryo’s structures] surrounded by a sphere of trophoblast cells [these cells form the embryo’s part of the placenta]) Because the ICM in the blastocyst is adhered to one part of the trophoblast ‘wall’ the rest of the space in the balstocyst is hollow (the blastocoel). Because of the presence of the blastocoel which previous to the formation of the blastocyst was occupied by multiple blastomere cells (what’s typical depicted in graphs of cell division from zygotes) it has been hypothesized that the blastocoel collapses and the collapse causes the cells to re-position themselves and ends up splitting the ICM into two separate new blastocysts (after the individual trophoblast cells move to seal the collapse site).

The formation of the blastocyst occurs after multiple divisions of the blastomeres (the first cells to divide in the embryo that collectively maintain the same volume as the original zygote) and it’s actually not referred to as a zygote anymore.

The cells in the ICM were split from a single blastocyst and were all derived from the same zygote so one could postulate that the souls were actually assigned to two set’s of different blastomeres. Maybe when the first two blastomeres were formed (the first cleavage) the BLASTOMERE’s are actually where souls were assigned. But the first cleavage (the production of the first two blastomeres) takes approximately 2 hours after fertilization so this would put a dent in the theory that the soul exists at Fertilization in both twins at the time of fertilization if we were to accept that souls are assigned to the first two blastomeres. But we could also disregard this time delay by saying that souls were assigned to the blastomeres and were inherent in them during their production, just like the soul of single zygotic child would be inherent during the production of the first two blastomeres (except that those two blastomeres contribute to one child).

Production of the first two blastomeres starts right after fertilization, so I think it would be safe to postulate that the souls were assigned during fertilization to the material that became the first two blastomeres and then that the blastomeres continue to cleave until they congregate as a single ICM in the blastocyst after which the blastomeres belonging to each respective soul are split by collapse of the blastocoel.

I’m not an embryologist but I’m pretty sure my description of Zygote–>Morula–>Blastocyst is correct.

This would be my guess!

Regards,
Mharren