Brain dead people are dead, just because a machine can keep your organs working doesn’t mean you are a person any more.

Some people want life to start at the start of the menstrual cycle, so its a “life” before its even fertilized. So I dismiss those nonsense arguments.

The discussion about abortion need not depend on the existence of the soul at all, or on religious belief. Many atheists are pro-life, and they certainly don’t believe in souls or in religion. The ethical treatment of human beings, including those in the womb, is about respect for life, and in particular about the obligation to protect innocent life.

Scientists agree that a human embryo, even when a zygote, is human. It isn’t a dog or a cow or a fish or an insect, planaria, or sponge. It can only be human, and since it is living, it is a human life.

Your argument is full of apparently unexamined presuppositions — about what life is, about what other people believe, about what is acceptable conduct. I can only hope that you come to understand that.

self-directing:
Directing or guiding oneself, especially as an independent agent.

That’s what the word means, an embryo, zygote, or egg does not fit those things, it doesn’t have a brain capable of thought, and its defiantly NOT independent

independent – free from external control and constraint

a skin cell isn’t a human, a brain cell isn’t a human

An embryo and zygote are both parasites of the mother.

You say it “just needs food” and “proper shelter” and It also need a lot more from the mother, it is incapable of surviving even a few minutes outside of the womb.

The umbilical cord transfers blood that that it needs if you cut the parasitic tie to the mother the organism dies.

Being able to “live outside of a womb” is not any part of what makes a particular organism human or not. It has nothing to do with it.

And the brain is not the only “self-directing” thing in a human. Of course, even a single cell directs itself. And early on, the fertilized human egg has all of the information, instructions and self-direction to grow into an adult human. He/she just needs food (nutrition) and proper shelter (womb) – BOTH things that EVERY human needs, regardless of their stage in life.

An embryo isn’t human, zygote isn’t human, an egg isn’t human, a cell isn’t human. I cant take any of those things outside of the mother and have it survive. Sorry it is not a “self-directing organism.” Its head doesn’t develop till week 7 so how can its brain function to support self-directing?

An embryo is a complete human life. It is an individual, unique, self-directing organism. All it needs is food and suitable shelter (just like the rest of us) and it will grow into an adult human being.

I want to be clear though. Technically, some consider a zygote (fertilized human egg) to be a “stem cell” as it’s totipotent (and eventually grows into an adult human).

But the stem cells I assume you are referring to are the embryonic/adult ones used for testing, etc…which are either pluripotent or multipotent – meaning that they can not ever form into their own organism. They are biologically very different and are a kind of cell that comes from the human organism itself. So no, they are not human persons by themselves. And no, it is not murder to “kill” such a stem cell.