I would ask two questions.
What is a Soul?
When does the Soul enter the Body?
When you know the answer to those questions, then I will listen to your definition of Who is and who is not yet Human. There is the Legal Definition, and then there is the definition of a much higher Authority. Best to memorize your argument, for when it is really going to count.
Questions that certainly will invoke varied responses, indeed. Some may attribute a definition to include the "spirit" while others may not.
There's a oft-quoted quote attributed to C.S. Lewis (though Wikiquote says it's misattributed) that says, "You donÂ’t have a soul. You are a soul. You have a body." That's how one person saw it.
Under that thinking, one can think of the soul as your total essence, and that could include things such as your body, your mind, your emotions. In theology, soul and spirit are often seen as separate entities, with the soul being who you are as a person, and the spirit as your communication or relationship with a higher power or creator.
If the soul is your entire being, then it has to be said that that comes from the beginning of its creation, conception. The body is certainly there, right from the human DNA code, and the rest comes from development.
What should be of importance is this: if one is unsure of a fetus' humanity, whether or not it can feel pain, whether or not it has some sense of consciousness, whether or not somebody defines it a person (a few of the classic arguments when finding "middle ground" on abortion), or when a "soul enters a body," it is best to err on the side of safety and protection, and especially on the side of the civil rights of this new human life.