I thought Catholic belief was that the soul is the animating force in the body, that the soul is the life itself, more important and valuable than the body. Are you saying it’s just a tag-along?
My two-cents is: not at all, it’s not a “tag-along.” It is, within the process of
coming-to-be, the animating and determining factor. As we mature, it becomes more and more pronounced - in other words, we become more and more different from one another. Also, we become more and more
alive. Our senses become more acute. Our drives become more and more intense. Our bodies become stronger and stronger. But, in time, all of this takes its toll. We become more and more alive, but, due to the fact that we are not infinite or perfect, we ultimately begin to wind down.
I guess I should also ask about the egg and sperm. These constituent parts already have souls because they come from bodies that have a soul.
It is true that they have souls, but, their souls are like the souls of animals. They are not the souls of a human being, in the ontological sense. Male cells have 23 paired chromosomes and a pattern, or form, for replication of itself-as-a-cell. The male
gamete cell, has one strand or chromosomes - not paired. It has no pattern for self-replication, so, in a few days, it just dies.
The addition of a second set of 23 unpaired chromosomes holds the key, so to speak, that unlocks the door for form (soul). There is a period of time, from the initial penetration of the sperm through the cell membrane of the ovum, and before the separate chromosome strands unite, that, so far as I know, has not been specifically addressed by the Church. That duration of time is very small, although it is my best guess that the Church will include that period of time within the statement that a human being starts at conception.
Yet they become part of a new body. Do they undergo some kind of soul transfer?
Actually, they complete the requisite for the fusion of form to matter, thus creating a new boy or girl, IOW, a new soul. The old, animal-level souls are cast out, or die, by natural causes.
jd