When does night become day? Loki's paradox. Development from sperm to a human is a cline (gradient). There is no magic moment. The scientific community does not hold that there is a magic moment.
Well, day becomes night when the sun dips below the horizon.
The scientific community is not interested in drawing a line at the point at which a being becomes fully human. Science simply observes and describes. Developmental biologists understand that human development continues throughout the lifespan from zygote through puberty through the reproductive years until death. You won't find labels from them because there is no point ever when the organism stops being human. They may have opinions, like you and I, but their opinion holds no more weight because that opinion is philosophical in nature.
You never answered my question. Given the choice of being a brain donor or a recipient which would you rather be?
A donor, obviously. But let's switch it up a little. Let's say two former fetuses have their brains surreptitiously switched immediately after birth. The parents will never know, since the newborns had no memories up to that point. So, does this make the newborns less of a human being than myself, the brain donor?
IMO: In the very least their needs to be the fundamental basis for our humanity. The ability to think, feel, self awareness. Unless you would be willing to throw your brain away and get a new brain then you understand this intuitively.
OK.
There's no doubt that fetuses have brain activity in the womb.
They react to maternal emotions. They react to external stimuli. They make facial expressions. So they are thinking and feeling in the womb, maybe not like you and I, but definitively nonetheless.
As for self-awareness, neonates are not self-aware.
Self-awareness doesn't fully develop until age 4 or 5. So, is a 2 year old not a full human being?
More germane to the topic at hand, at what point in the continuum of development is a human being worthy of protection by society? This is not something we get to decide individually. What if a woman decides that her two-month old is too much of a burden and she suffocates it? Obviously, at some point, we have to decide as a society at what point we will protect that human.
In the present case, Texas has drawn the line at 20 weeks. The rationale is that the fetus can feel pain at this point. Of course, this is a controversial claim. However, there is no doubt that at 20 weeks, fetal neural development is well underway; in fact,
by embryonic day 108 (approximately 17 weeks), cortical neurogenesis is complete. Brain development is rapid after this point. So while there really isn't any empirical evidence that the fetus feels pain, it remains eminently possible due to the advanced development of the nervous system at this point. I think 20 weeks is a reasonable estimate for a different reason: It's on the cusp of viability, which is SCOTUS' legal line. We'll see if it holds up.
Your body is the least important aspect of you. What makes you "a human" are your memories and your ability to think and feel. What makes two identical twins different? Different life's experiences. Different memories.
This implies, then, that very young infants are not individuals. Yet, I'm quite sure you don't advocate that they can be killed.
What is the process?
Temple Grandin explains it perfectly in her thesis
Animals Are Not Things.
What process? The development of a nervous system. Until then the tissue cannot suffer. It cannot hope for the future. It cannot appreciate its existence in any sense.
That's the process.
As I pointed out earlier, the nervous system is highly developed by week 17. The paper I linked to points out that by week 26, the sensory and motor pathways are completely formed. It also points out that neural development continues postnatally. Also, infants can't hope for the future or appreciate their existences, as the other paper on the development of self-awareness I linked to explains. So are infants not human beings?