Without a body, there is no soul. Souls are made to make bodies alive, so they are created at conception. The pre-existence of souls is both philosophically and theologically (in the Catholic Faith) unacceptable.
The human soul lives after the body dies, but it’s still a “body animating thing”, and is incomplete until the Resurrection, when it can perform all of its functions again.
There is no official Church teaching as to exactly when the soul is created. We would assume that since the Church does teach that we are a body/soul unity that the soul is created by God at conception…teachccd
365 The unity of soul and body is so profound that one has to consider the soul to be the “form” of the body:234 i.e., it is because of its spiritual soul that the body made of matter becomes a living, human body; spirit and matter, in man, are not two natures united, but rather their union forms a single nature. [366](javascriptpenWindow(‘cr/366.htm’) The Church teaches that every spiritual soul is created immediately by God - it is not “produced” by the parents - and also that it is immortal: it does not perish when it separates from the body at death, and it will be reunited with the body at the final Resurrection.235
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