Starwynd:
You have asked one, tough question! Why, because of the usual lack of honest communication between people, regardless of which side they choose. “Honest communication” is more than the act of speaking to another in a kindly and sincere manner. It includes taking the time to make serious inquiries into the epistemology of the subject under discussion. If one wanted to enter into a discussion about “flying” with a pilot, one ought to first study the subject. Too many people enter these discussions with too little knowledge, and too much unsubstantiated opinion.
For Catholics, the creation, by God, of the soul takes place at the front-end of the “moment of existence” of the zygote – the very first and smallest slice of time possible, as the baby comes to be. Here’s how:
First we must understand the concept of “motion” and agree to its reality, for motion is all we know through our senses. It is all that our senses deliver to our minds.
For Aristotle, “coming-to-be” was analogous with, and its predicates were the same as, the predicates of “motion”. To explain: if my left hand is raised straight up from my body and to the body’s left aspect, and, shortly thereafter, it shifts to the right side of my body, it went through a motion-process. While on the left side of my body, my hand was predicated to be in “potency” - what “potency”? - the potency to be on the right.
Once my hand is on the right, my hand is now predicated to be in “act”. (It is “actually” there, or, “actualized” in that place, if you will.) My hand “moved” from “potency” to “act”. (Of course, for “local motion”, the process may be repeated many more times, but, it’s irrelevant here.) The process of “coming-to-be”, for Aristotle was this process or “movement” from potency to act.
These are the knowable predicates of the process of “coming to be”, “potency” and “act”. These we can “know” scientifically. Under the microscope, we can view the spermatozoon enter and combine with the oocyte; we can watch the chromosomes line up; and, we can see the resulting zygote. The next part is where people have a more difficult time in the communication cycle: this is where the materialist, i.e., atheist, disconnects from communication, because, for him, there is no reason to proceed any further. For the theist, there are other considerations, or realities, such as perceptions of the metaphysical universe, the phenomena of miracles, and, his faith, that shape his thinking.
For the theist, the physical process we have just witnessed and understood must now be “converted”, in a sense, to a metaphysical process. For Aristotle, the metaphysical is understood by knowing how a piece of clay - molded into the form of a thing - comes to be a statue. Metaphysical coming to be is, thus, predicated through the lens of the physical. So, in the same manner, the Creator takes a piece of matter and gives it its existence, its uniqueness, its anima, its “form”. We give a name to the matter from which God pulls to put “form” to; we call it, “primary matter”.
The “anima” put to the “primary matter” is what gives the matter its “being”, “life”, “form”. The end-being becomes this particular man or that particular woman. The combining of form and primary matter is the process of “coming to be”, a “moving” from potency to act. Thus, the soul is the combination of matter and form, it is the “act” of the potential. The resultant being is so unique that it could not have been extant prior to its “act”. (This is the Catholic argument against “reincarnation”.) Furthermore, it consists inextricably of both its matter and its form.
The early Church affirmed this explanation, but, it was not as well understood until the time of St. Thomas. He found no failure in Aristotle’s explanation and was able to rather thoroughly define and expand upon it.
The concept of the “soul” as some kind of “ethereal spirit”, etc., is something created by men who perhaps did/could not understand the Aristotelian-Thomistic notion of the “soul” and, for simplicity’s sake, called it a “spirit” - some ethereal thing that resides somewhere in the body, near the brain, maybe. Some definitions are in order: (a) the “brain” is a physical organ of the body and it is that which “houses” the “mind”; (b) the “mind” is that which “learns” and “reasons”; and is housed in the brain, and (c), the “soul” is the “being” itself that, along with the senses, “informs” the mind and eventually passes on to heaven, hell, or in between. The word “spirit” has several meanings (“vivacity”; removed quickly, as in “spirited away”; and “soul”) of which only one is relevant.
JD